explainWhyTypeIsComptime is extremely verbose

[Vexu]

Assigning the result of @typeInfo to a non-comptime variable:

test {
    var a = @typeInfo(u32);
    _ = a;
}

..will produce 159 lines of errors:

$ zig2 test a.zig
a.zig:2:9: error: variable of type 'builtin.Type' must be const or comptime
    var a = @typeInfo(u32);
        ^
./zig-out/lib/zig/std/builtin.zig:198:10: note: union requires comptime because of this field
    Int: Int,
         ^~~
./zig-out/lib/zig/std/builtin.zig:225:15: note: struct requires comptime because of this field
        bits: comptime_int,
              ^~~~~~~~~~~~
./zig-out/lib/zig/std/builtin.zig:199:12: note: union requires comptime because of this field
    Float: Float,
           ^~~~~
./zig-out/lib/zig/std/builtin.zig:232:15: note: struct requires comptime because of this field
        bits: comptime_int,
              ^~~~~~~~~~~~
./zig-out/lib/zig/std/builtin.zig:200:14: note: union requires comptime because of this field
    Pointer: Pointer,
             ^~~~~~~
./zig-out/lib/zig/std/builtin.zig:242:20: note: struct requires comptime because of this field
        alignment: comptime_int,
                   ^~~~~~~~~~~~
./zig-out/lib/zig/std/builtin.zig:244:16: note: struct requires comptime because of this field
        child: type,
               ^~~~
./zig-out/lib/zig/std/builtin.zig:244:16: note: types are not available at runtime
        child: type,
               ^~~~
./zig-out/lib/zig/std/builtin.zig:201:12: note: union requires comptime because of this field
    Array: Array,
           ^~~~~
./zig-out/lib/zig/std/builtin.zig:265:14: note: struct requires comptime because of this field
        len: comptime_int,
             ^~~~~~~~~~~~
./zig-out/lib/zig/std/builtin.zig:266:16: note: struct requires comptime because of this field
        child: type,
               ^~~~
./zig-out/lib/zig/std/builtin.zig:266:16: note: types are not available at runtime
        child: type,
               ^~~~
./zig-out/lib/zig/std/builtin.zig:202:13: note: union requires comptime because of this field
    Struct: Struct,
            ^~~~~~
./zig-out/lib/zig/std/builtin.zig:297:17: note: struct requires comptime because of this field
        fields: []const StructField,
                ^~~~~~~~~~~~~~~~~~~
./zig-out/lib/zig/std/builtin.zig:287:21: note: struct requires comptime because of this field
        field_type: type,
                    ^~~~
./zig-out/lib/zig/std/builtin.zig:287:21: note: types are not available at runtime
        field_type: type,
                    ^~~~
./zig-out/lib/zig/std/builtin.zig:290:20: note: struct requires comptime because of this field
        alignment: comptime_int,
                   ^~~~~~~~~~~~
./zig-out/lib/zig/std/builtin.zig:207:15: note: union requires comptime because of this field
    Optional: Optional,
              ^~~~~~~~
./zig-out/lib/zig/std/builtin.zig:305:16: note: struct requires comptime because of this field
        child: type,
               ^~~~
./zig-out/lib/zig/std/builtin.zig:305:16: note: types are not available at runtime
        child: type,
               ^~~~
./zig-out/lib/zig/std/builtin.zig:208:17: note: union requires comptime because of this field
    ErrorUnion: ErrorUnion,
                ^~~~~~~~~~
./zig-out/lib/zig/std/builtin.zig:311:20: note: struct requires comptime because of this field
        error_set: type,
                   ^~~~
./zig-out/lib/zig/std/builtin.zig:311:20: note: types are not available at runtime
        error_set: type,
                   ^~~~
./zig-out/lib/zig/std/builtin.zig:312:18: note: struct requires comptime because of this field
        payload: type,
                 ^~~~
./zig-out/lib/zig/std/builtin.zig:312:18: note: types are not available at runtime
        payload: type,
                 ^~~~
./zig-out/lib/zig/std/builtin.zig:210:11: note: union requires comptime because of this field
    Enum: Enum,
          ^~~~
./zig-out/lib/zig/std/builtin.zig:337:19: note: struct requires comptime because of this field
        tag_type: type,
                  ^~~~
./zig-out/lib/zig/std/builtin.zig:337:19: note: types are not available at runtime
        tag_type: type,
                  ^~~~
./zig-out/lib/zig/std/builtin.zig:338:17: note: struct requires comptime because of this field
        fields: []const EnumField,
                ^~~~~~~~~~~~~~~~~
./zig-out/lib/zig/std/builtin.zig:329:16: note: struct requires comptime because of this field
        value: comptime_int,
               ^~~~~~~~~~~~
./zig-out/lib/zig/std/builtin.zig:211:12: note: union requires comptime because of this field
    Union: Union,
           ^~~~~
./zig-out/lib/zig/std/builtin.zig:355:19: note: struct requires comptime because of this field
        tag_type: ?type,
                  ^~~~~
./zig-out/lib/zig/std/builtin.zig:355:19: note: types are not available at runtime
        tag_type: ?type,
                  ^~~~~
./zig-out/lib/zig/std/builtin.zig:356:17: note: struct requires comptime because of this field
        fields: []const UnionField,
                ^~~~~~~~~~~~~~~~~~
./zig-out/lib/zig/std/builtin.zig:347:21: note: struct requires comptime because of this field
        field_type: type,
                    ^~~~
./zig-out/lib/zig/std/builtin.zig:347:21: note: types are not available at runtime
        field_type: type,
                    ^~~~
./zig-out/lib/zig/std/builtin.zig:348:20: note: struct requires comptime because of this field
        alignment: comptime_int,
                   ^~~~~~~~~~~~
./zig-out/lib/zig/std/builtin.zig:212:9: note: union requires comptime because of this field
    Fn: Fn,
        ^~
./zig-out/lib/zig/std/builtin.zig:367:20: note: struct requires comptime because of this field
        alignment: comptime_int,
                   ^~~~~~~~~~~~
./zig-out/lib/zig/std/builtin.zig:371:22: note: struct requires comptime because of this field
        return_type: ?type,
                     ^~~~~
./zig-out/lib/zig/std/builtin.zig:371:22: note: types are not available at runtime
        return_type: ?type,
                     ^~~~~
./zig-out/lib/zig/std/builtin.zig:372:15: note: struct requires comptime because of this field
        args: []const Param,
              ^~~~~~~~~~~~~
./zig-out/lib/zig/std/builtin.zig:379:23: note: struct requires comptime because of this field
            arg_type: ?type,
                      ^~~~~
./zig-out/lib/zig/std/builtin.zig:379:23: note: types are not available at runtime
            arg_type: ?type,
                      ^~~~~
./zig-out/lib/zig/std/builtin.zig:213:14: note: union requires comptime because of this field
    BoundFn: Fn,
             ^~
./zig-out/lib/zig/std/builtin.zig:216:15: note: union requires comptime because of this field
    AnyFrame: AnyFrame,
              ^~~~~~~~
./zig-out/lib/zig/std/builtin.zig:398:16: note: struct requires comptime because of this field
        child: ?type,
               ^~~~~
./zig-out/lib/zig/std/builtin.zig:398:16: note: types are not available at runtime
        child: ?type,
               ^~~~~
./zig-out/lib/zig/std/builtin.zig:217:13: note: union requires comptime because of this field
    Vector: Vector,
            ^~~~~~
./zig-out/lib/zig/std/builtin.zig:404:14: note: struct requires comptime because of this field
        len: comptime_int,
             ^~~~~~~~~~~~
./zig-out/lib/zig/std/builtin.zig:405:16: note: struct requires comptime because of this field
        child: type,
               ^~~~
./zig-out/lib/zig/std/builtin.zig:405:16: note: types are not available at runtime
        child: type,
               ^~~~

.. which is a bit excessive.

I think it should either only report the first comptime field or just drop all the other notes after a certain limit and mention that there were more reasons.

Follow up to #12324