[liftoff] Add code comments for large stack checks

This adds a code comment before the OOL code for the special stack check
for a large frame. Otherwise it is hard to see where it begins in the
code, and it might be unexpected to see that block of code at the end of
a Liftoff function.

Drive-by: Replace another "out of line: " comment by "OOL: ", which is
typically understood equally well.

R=ahaas@chromium.org

Bug: v8:12017
Change-Id: Ie8b243cedebe979ca46e0515a9fdd0695ab58304
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3059081
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75995}

src/wasm/baseline/arm/liftoff-assembler-arm.h

@@ -518,6 +518,7 @@ void LiftoffAssembler::PatchPrepareStackFrame(
   // If the frame is bigger than the stack, we throw the stack overflow
   // exception unconditionally. Thereby we can avoid the integer overflow
   // check in the condition code.
+  RecordComment("OOL: stack check for large frame");
   Label continuation;
   if (frame_size < FLAG_stack_size * 1024) {
     UseScratchRegisterScope temps(this);

src/wasm/baseline/arm64/liftoff-assembler-arm64.h

@@ -346,6 +346,7 @@ void LiftoffAssembler::PatchPrepareStackFrame(
   // If the frame is bigger than the stack, we throw the stack overflow
   // exception unconditionally. Thereby we can avoid the integer overflow
   // check in the condition code.
+  RecordComment("OOL: stack check for large frame");
   Label continuation;
   if (frame_size < FLAG_stack_size * 1024) {
     UseScratchRegisterScope temps(this);

src/wasm/baseline/ia32/liftoff-assembler-ia32.h

@@ -266,6 +266,7 @@ void LiftoffAssembler::PatchPrepareStackFrame(
   // If the frame is bigger than the stack, we throw the stack overflow
   // exception unconditionally. Thereby we can avoid the integer overflow
   // check in the condition code.
+  RecordComment("OOL: stack check for large frame");
   Label continuation;
   if (frame_size < FLAG_stack_size * 1024) {
     // We do not have a scratch register, so pick any and push it first.

src/wasm/baseline/liftoff-compiler.cc

@@ -847,7 +847,7 @@ class LiftoffCompiler {
 
   void GenerateOutOfLineCode(OutOfLineCode* ool) {
     CODE_COMMENT(
-        (std::string("out of line: ") + GetRuntimeStubName(ool->stub)).c_str());
+        (std::string("OOL: ") + GetRuntimeStubName(ool->stub)).c_str());
     __ bind(ool->label.get());
     const bool is_stack_check = ool->stub == WasmCode::kWasmStackGuard;
 

src/wasm/baseline/x64/liftoff-assembler-x64.h

@@ -252,6 +252,7 @@ void LiftoffAssembler::PatchPrepareStackFrame(
   // If the frame is bigger than the stack, we throw the stack overflow
   // exception unconditionally. Thereby we can avoid the integer overflow
   // check in the condition code.
+  RecordComment("OOL: stack check for large frame");
   Label continuation;
   if (frame_size < FLAG_stack_size * 1024) {
     movq(kScratchRegister,