[JSC] Enable 16bit CLoop Win

https://bugs.webkit.org/show_bug.cgi?id=198283
rdar://128344991

Reviewed by Ross Kirsling.

This was MSVC workaround. Now we only support clang-cl, so we do not need this workaround.

* Source/JavaScriptCore/generator/Opcode.rb:
* Source/JavaScriptCore/llint/LowLevelInterpreter.asm:
* Source/JavaScriptCore/llint/LowLevelInterpreter32_64.asm:

Canonical link: https://commits.webkit.org/278968@main

Source/JavaScriptCore/generator/Opcode.rb

@@ -236,12 +236,6 @@ def emitter
     static bool checkImpl(BytecodeGenerator* gen#{typed_reference_args}#{metadata_param})
     {
         UNUSED_PARAM(gen);
-#if OS(WINDOWS) && ENABLE(C_LOOP)
-        // FIXME: Disable wide16 optimization for Windows CLoop
-        // https://bugs.webkit.org/show_bug.cgi?id=198283
-        if (__size == OpcodeSize::Wide16)
-            return false;
-#endif
         return #{map_fields_with_size("", "__size", &:fits_check).join "\n            && "}
             && (__size == OpcodeSize::Narrow ? #{Argument.new("opcodeID", opcodeIDType, 0).fits_check(Size::Narrow)} : #{Argument.new("opcodeID", opcodeIDType, 0).fits_check(Size::Wide16)})
             && (__size == OpcodeSize::Wide16 ? #{op_wide16.fits_check(Size::Narrow)} : true)

Source/JavaScriptCore/llint/LowLevelInterpreter.asm

@@ -467,19 +467,13 @@ _%label%:
         break
     end
 
-# FIXME: We cannot enable wide16 bytecode in Windows CLoop. With MSVC, as CLoop::execute gets larger code
-# size, CLoop::execute gets higher stack height requirement. This makes CLoop::execute takes 160KB stack
-# per call, causes stack overflow error easily. For now, we disable wide16 optimization for Windows CLoop.
-# https://bugs.webkit.org/show_bug.cgi?id=198283
-if not C_LOOP_WIN
 _%label%_wide16:
     prologue()
     fn(wide16)
     if ASSERT_ENABLED
         break
         break
     end
-end
 
 _%label%_wide32:
     prologue()
@@ -1083,21 +1077,15 @@ end
 
 macro defineReturnLabel(opcodeName, size)
     macro defineNarrow()
-        if not C_LOOP_WIN
-            _%opcodeName%_return_location:
-        end
+        _%opcodeName%_return_location:
     end
 
     macro defineWide16()
-        if not C_LOOP_WIN
-            _%opcodeName%_return_location_wide16:
-        end
+        _%opcodeName%_return_location_wide16:
     end
 
     macro defineWide32()
-        if not C_LOOP_WIN
-            _%opcodeName%_return_location_wide32:
-        end
+        _%opcodeName%_return_location_wide32:
     end
 
     size(defineNarrow, defineWide16, defineWide32, macro (f) f() end)

Source/JavaScriptCore/llint/LowLevelInterpreter32_64.asm

@@ -196,8 +196,6 @@ macro cCall4(function)
         push a0
         call function
         addp 16, sp
-    elsif C_LOOP or C_LOOP_WIN
-        error
     else
         error
     end