swift-ide-test: Allow objc-interop to be configured

This adds a -disable-objc-interop flag to allow objc-interop
to be disabled, and an -enable-objc-interop flag to
allow objc-interop to be enabled.

Objc interop will default to enabled on darwin, and disabled on
other platforms.

Author: fjricci

tools/swift-ide-test/swift-ide-test.cpp

@@ -636,6 +636,16 @@ static llvm::cl::opt<bool> DebugConstraintSolver("debug-constraints",
 static llvm::cl::opt<bool>
 IncludeLocals("include-locals", llvm::cl::desc("Index local symbols too."),
               llvm::cl::cat(Category), llvm::cl::init(false));
+
+static llvm::cl::opt<bool>
+    EnableObjCInterop("enable-objc-interop",
+                      llvm::cl::desc("Enable ObjC interop."),
+                      llvm::cl::cat(Category), llvm::cl::init(false));
+
+static llvm::cl::opt<bool>
+    DisableObjCInterop("disable-objc-interop",
+                       llvm::cl::desc("Disable ObjC interop."),
+                       llvm::cl::cat(Category), llvm::cl::init(false));
 } // namespace options
 
 static std::unique_ptr<llvm::MemoryBuffer>
@@ -3005,6 +3015,14 @@ int main(int argc, char *argv[]) {
         InitInvok.getLangOptions().EffectiveLanguageVersion = actual.getValue();
     }
   }
+  if (options::DisableObjCInterop) {
+    InitInvok.getLangOptions().EnableObjCInterop = false;
+  } else if (options::EnableObjCInterop) {
+    InitInvok.getLangOptions().EnableObjCInterop = true;
+  } else {
+    InitInvok.getLangOptions().EnableObjCInterop =
+        llvm::Triple(InitInvok.getTargetTriple()).isOSDarwin();
+  }
   InitInvok.getClangImporterOptions().ModuleCachePath =
     options::ModuleCachePath;
   InitInvok.getClangImporterOptions().PrecompiledHeaderOutputDir =