Remove IRGenOptions objc-interop flag.

Swift SVN r23166

include/swift/AST/IRGenOptions.h

@@ -93,15 +93,12 @@ public:
   /// Special codegen for playgrounds.
   unsigned Playground : 1;
 
-  /// Enable Objective-C interop code generation
-  unsigned EnableObjCInterop : 1;
-
   IRGenOptions() : OutputKind(IRGenOutputKind::LLVMAssembly), Verify(true),
                    Optimize(false), DebugInfo(false), UseJIT(false),
                    EnableDynamicValueTypeLayout(false),
                    DisableLLVMOptzns(false), DisableLLVMARCOpts(false),
                    DisableFPElim(true), HasUnderlyingModule(false),
-                   Playground(false), EnableObjCInterop(true) {}
+                   Playground(false) {}
 };
 
 } // end namespace swift

lib/Frontend/CompilerInvocation.cpp

@@ -947,12 +947,6 @@ static bool ParseIRGenArgs(IRGenOptions &Opts, ArgList &Args,
   if (const Arg *A = Args.getLastArg(OPT_target))
     Opts.Triple = llvm::Triple::normalize(A->getValue());
 
-  if (auto A = Args.getLastArg(OPT_enable_objc_interop,
-                               OPT_disable_objc_interop)) {
-    Opts.EnableObjCInterop
-      = A->getOption().matches(OPT_enable_objc_interop);
-  }
-
   // TODO: investigate whether these should be removed, in favor of definitions
   // in other classes.
   if (FrontendOpts.PrimaryInput && FrontendOpts.PrimaryInput->isFilename()) {

lib/IRGen/IRGenModule.cpp

@@ -97,7 +97,7 @@ IRGenModule::IRGenModule(ASTContext &Context,
     Module(*ClangCodeGen->GetModule()),
     LLVMContext(Module.getContext()), DataLayout(DataLayout),
     SILMod(SILMod), TargetInfo(SwiftTargetInfo::get(*this)),
-    DebugInfo(0), ObjCInterop(Opts.EnableObjCInterop),
+    DebugInfo(0), ObjCInterop(Context.LangOpts.EnableObjCInterop),
     Types(*new TypeConverter(*this))
 {
   VoidTy = llvm::Type::getVoidTy(getLLVMContext());