[SourceKit] Sanitize -embed-bitcode flag to avoid crashing. rdar://22874139

Author: nkcsgexi

test/SourceKit/SourceDocInfo/cursor_overrides.swift

@@ -16,7 +16,7 @@ func goo(x: SubCls) {
   x.meth()
 }
 
-// RUN: %sourcekitd-test -req=cursor -pos=16:7 %s -- -triple x86_64-apple-macosx10.9 -I %S/Inputs/cursor-overrides %mcp_opt %s | FileCheck -check-prefix=CHECK1 %s
+// RUN: %sourcekitd-test -req=cursor -pos=16:7 %s -- -embed-bitcode -triple x86_64-apple-macosx10.9 -I %S/Inputs/cursor-overrides %mcp_opt %s | FileCheck -check-prefix=CHECK1 %s
 // CHECK1: source.lang.swift.ref.function.method.instance (12:8-12:14)
 // CHECK1: s:FC16cursor_overrides6SubCls4methFT_T_
 // CHECK1: SubCls -> () -> ()

tools/SourceKit/lib/SwiftLang/SwiftASTManager.cpp

@@ -364,6 +364,8 @@ static void sanitizeCompilerArgs(ArrayRef<const char *> Args,
       continue;
     if (Arg == "-Xfrontend")
       continue;
+    if (Arg == "-embed-bitcode")
+      continue;
     NewArgs.push_back(CArg);
   }
 }