[Clang][Win][JSC] dfg/DFGJITCode.h(163,18): warning: unqualified frie…

…nd declaration referring to type outside of the nearest enclosing namespace is a Microsoft extension

https://bugs.webkit.org/show_bug.cgi?id=255504

Reviewed by Ross Kirsling.

clang-cl reported the following 2 warnings for Windows port.

> dfg/DFGJITCode.h(163,18): warning: unqualified friend declaration referring to type outside of the nearest enclosing namespace is a Microsoft extension; add a nested name specifier [-Wmicrosoft-unqualified-friend]
>     friend class LLIntOffsetsExtractor;
>                  ^
>                  ::JSC::
> dfg\DFGSpeculativeJIT.h(1032,5): warning: non-void function does not return a value [-Wreturn-type]

* Source/JavaScriptCore/dfg/DFGJITCode.h:
* Source/JavaScriptCore/dfg/DFGSpeculativeJIT.h:
(JSC::DFG::SpeculativeJIT::appendCallWithUGPRPair):

Canonical link: https://commits.webkit.org/263013@main

Source/JavaScriptCore/dfg/DFGJITCode.h

@@ -160,7 +160,7 @@ class LinkerIR {
 
 class JITData final : public TrailingArray<JITData, void*> {
     WTF_MAKE_FAST_ALLOCATED;
-    friend class LLIntOffsetsExtractor;
+    friend class JSC::LLIntOffsetsExtractor;
 public:
     using Base = TrailingArray<JITData, void*>;
     using ExitVector = FixedVector<MacroAssemblerCodeRef<OSRExitPtrTag>>;

Source/JavaScriptCore/dfg/DFGSpeculativeJIT.h

@@ -1024,7 +1024,7 @@ class SpeculativeJIT : public JITCompiler {
     }
 
 #if OS(WINDOWS) && CPU(X86_64)
-    JITCompiler::Call appendCallWithUGPRPair(Address address)
+    void appendCallWithUGPRPair(Address address)
     {
         prepareForExternalCall();
         emitStoreCodeOrigin(m_currentNode->origin.semantic);