Auto merge of #93836 - matthiaskrgr:rollup-d1ssiwl, r=matthiaskrgr

Rollup of 6 pull requests

Successful merges:

 - #91443 (Better suggestions when user tries to collect into an unsized `[_]`)
 - #91504 (`#[used(linker)]` attribute)
 - #93503 (debuginfo: Fix DW_AT_containing_type vtable debuginfo regression)
 - #93753 (Complete removal of #[main] attribute from compiler)
 - #93799 (Fix typo in `std::fmt` docs)
 - #93813 (Make a few cleanup MIR passes public)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

compiler/rustc_codegen_gcc/src/consts.rs

@@ -144,7 +144,7 @@ impl<'gcc, 'tcx> StaticMethods for CodegenCx<'gcc, 'tcx> {
             // TODO(antoyo): set link section.
         }
 
-        if attrs.flags.contains(CodegenFnAttrFlags::USED) {
+        if attrs.flags.contains(CodegenFnAttrFlags::USED) || attrs.flags.contains(CodegenFnAttrFlags::USED_LINKER) {
             self.add_used_global(global.to_rvalue());
         }
     }

compiler/rustc_codegen_llvm/src/consts.rs

@@ -522,6 +522,9 @@ impl<'ll> StaticMethods for CodegenCx<'ll, '_> {
             }
 
             if attrs.flags.contains(CodegenFnAttrFlags::USED) {
+                // `USED` and `USED_LINKER` can't be used together.
+                assert!(!attrs.flags.contains(CodegenFnAttrFlags::USED_LINKER));
+
                 // The semantics of #[used] in Rust only require the symbol to make it into the
                 // object file. It is explicitly allowed for the linker to strip the symbol if it
                 // is dead. As such, use llvm.compiler.used instead of llvm.used.
@@ -530,6 +533,12 @@ impl<'ll> StaticMethods for CodegenCx<'ll, '_> {
                 // in some versions of the gold linker.
                 self.add_compiler_used_global(g);
             }
+            if attrs.flags.contains(CodegenFnAttrFlags::USED_LINKER) {
+                // `USED` and `USED_LINKER` can't be used together.
+                assert!(!attrs.flags.contains(CodegenFnAttrFlags::USED));
+
+                self.add_used_global(g);
+            }
         }
     }