[sourcekitd] Filter out -v flag

We really need to use the driver for this and stop doing ad-hoc
filtering (rdar://17897287), for for now keep limping along...

rdar://35424741

tools/SourceKit/lib/SwiftLang/SwiftASTManager.cpp

@@ -377,6 +377,8 @@ static void sanitizeCompilerArgs(ArrayRef<const char *> Args,
       continue;
     if (Arg == "-c")
       continue;
+    if (Arg == "-v")
+      continue;
     if (Arg == "-Xfrontend")
       continue;
     if (Arg == "-embed-bitcode")