[PATCH] Add flag -f(no-)modules-implicit-maps.

[Richard Smith]

One comment to address, then please go ahead and commit.

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Comment at: lib/Frontend/CompilerInvocation.cpp:1467
@@ -1465,1 +1466,3 @@
+      Args.hasFlag(OPT_fmodules_implicit_maps, OPT_fno_modules_implicit_maps,
+                   Opts.ModulesImplicitMaps);
   Opts.CharIsSigned = Opts.OpenCL || !Args.hasArg(OPT_fno_signed_char);
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You're initializing this from itself if neither flag is set. Did you mean `Opts.Modules` or `Opts.ModuleMaps`, or maybe `true`?

http://reviews.llvm.org/D6305