fix: compile incrementors in for loops within the initializer's flow

src/compiler.ts

@@ -2600,6 +2600,7 @@ export class Compiler extends DiagnosticEmitter {
     if (possiblyLoops) {
       let incrementor = statement.incrementor;
       if (incrementor) {
+        this.currentFlow = flow;
         bodyStmts.push(
           this.compileExpression(incrementor, Type.void, Constraints.ConvImplicit | Constraints.WillDrop)
         );

tests/compiler/issues/2825.debug.wat

@@ -0,0 +1,55 @@
+(module
+ (type $0 (func))
+ (type $1 (func (param i32 i32 i32 i32)))
+ (type $2 (func (param i32) (result i32)))
+ (import "env" "abort" (func $~lib/builtins/abort (param i32 i32 i32 i32)))
+ (global $~lib/memory/__data_end i32 (i32.const 60))
+ (global $~lib/memory/__stack_pointer (mut i32) (i32.const 32828))
+ (global $~lib/memory/__heap_base i32 (i32.const 32828))
+ (memory $0 1)
+ (data $0 (i32.const 12) ",\00\00\00\00\00\00\00\00\00\00\00\02\00\00\00\1c\00\00\00i\00s\00s\00u\00e\00s\00/\002\008\002\005\00.\00t\00s\00")
+ (table $0 1 1 funcref)
+ (elem $0 (i32.const 1))
+ (export "memory" (memory $0))
+ (start $~start)
+ (func $issues/2825/increment (param $x i32) (result i32)
+  local.get $x
+  i32.const 1234
+  i32.ne
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 32
+   i32.const 2
+   i32.const 3
+   call $~lib/builtins/abort
+   unreachable
+  end
+  local.get $x
+  i32.const 1
+  i32.add
+  return
+ )
+ (func $start:issues/2825
+  (local $i i32)
+  (local $i|1 i32)
+  i32.const 0
+  local.set $i
+  loop $for-loop|0
+   local.get $i
+   i32.const 10
+   i32.lt_s
+   if
+    i32.const 1234
+    local.set $i|1
+    local.get $i
+    call $issues/2825/increment
+    local.set $i
+    br $for-loop|0
+   end
+  end
+ )
+ (func $~start
+  call $start:issues/2825
+ )
+)

tests/compiler/issues/2825.json

@@ -0,0 +1 @@
+{}

tests/compiler/issues/2825.release.wat

@@ -0,0 +1,36 @@
+(module
+ (type $0 (func (param i32 i32 i32 i32)))
+ (type $1 (func))
+ (import "env" "abort" (func $~lib/builtins/abort (param i32 i32 i32 i32)))
+ (memory $0 1)
+ (data $0 (i32.const 1036) ",")
+ (data $0.1 (i32.const 1048) "\02\00\00\00\1c\00\00\00i\00s\00s\00u\00e\00s\00/\002\008\002\005\00.\00t\00s")
+ (export "memory" (memory $0))
+ (start $~start)
+ (func $~start
+  (local $0 i32)
+  loop $for-loop|0
+   local.get $0
+   i32.const 10
+   i32.lt_s
+   if
+    local.get $0
+    i32.const 1234
+    i32.eq
+    if
+     i32.const 0
+     i32.const 1056
+     i32.const 2
+     i32.const 3
+     call $~lib/builtins/abort
+     unreachable
+    end
+    local.get $0
+    i32.const 1
+    i32.add
+    local.set $0
+    br $for-loop|0
+   end
+  end
+ )
+)

tests/compiler/issues/2825.ts

@@ -0,0 +1,8 @@
+function increment(x: i32): i32 {
+  assert(x !== 1234);
+  return x + 1;
+}
+
+for (let i = 0; i < 10; i = increment(i)) {
+  let i = 1234;
+}