modulewrap: Disable ObjC interop by default on non-Darwin platforms

0a5653d started to call
`IGM.finalize()`, which leads the Clang instance to emit ObjC metadata
sections when the ObjC interop is enabled. Emitting ObjC metadata
sections is not well supported on non-Darwin platforms and causes
crashes for WebAssembly and COFF object formats[^1].

modulewrap tool did not configure the ObjC interop option, so it always
enabled the ObjC interop. This patch aligns the default ObjC interop
value with other tools by disabling it on non-Darwin platforms.

[^1]: https://github.com/apple/llvm-project/blob/stable/20230725/clang/lib/CodeGen/CGObjCMac.cpp#L5068-L5074

Author: kateinoigakukun

lib/DriverTool/modulewrap_main.cpp

@@ -48,6 +48,7 @@ class ModuleWrapInvocation {
   llvm::Triple TargetTriple;
   std::vector<std::string> InputFilenames;
   bool UseSharedResourceFolder = true;
+  bool EnableObjCInterop = true;
 
 public:
   bool hasSingleInput() const { return InputFilenames.size() == 1; }
@@ -65,6 +66,7 @@ class ModuleWrapInvocation {
   llvm::Triple &getTargetTriple() { return TargetTriple; }
 
   bool useSharedResourceFolder() { return UseSharedResourceFolder; }
+  bool enableObjCInterop() { return EnableObjCInterop; }
 
   int parseArgs(llvm::ArrayRef<const char *> Args, DiagnosticEngine &Diags) {
     using namespace options;
@@ -124,6 +126,9 @@ class ModuleWrapInvocation {
       UseSharedResourceFolder = false;
     }
 
+    EnableObjCInterop = ParsedArgs.hasFlag(OPT_enable_objc_interop,
+        OPT_disable_objc_interop, TargetTriple.isOSDarwin());
+
     return 0;
   }
 };
@@ -184,6 +189,7 @@ int modulewrap_main(ArrayRef<const char *> Args, const char *Argv0,
   symbolgraphgen::SymbolGraphOptions SymbolGraphOpts;
   CASOptions CASOpts;
   LangOpts.Target = Invocation.getTargetTriple();
+  LangOpts.EnableObjCInterop = Invocation.enableObjCInterop();
   ASTContext &ASTCtx = *ASTContext::get(
       LangOpts, TypeCheckOpts, SILOpts, SearchPathOpts, ClangImporterOpts,
       SymbolGraphOpts, CASOpts, SrcMgr, Instance.getDiags(),