[modules] Flatten -fmodule-name= and -fmodule-implementation-of= into a single
option. Previously these options could both be used to specify that you were
compiling the implementation file of a module, with a different set of minor
bugs in each case.

This change removes -fmodule-implementation-of, and instead tracks a flag to
determine whether we're currently building a module. -fmodule-name now behaves
the same way that -fmodule-implementation-of previously did.

llvm-svn: 261372
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index 8441a91..584dfed 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -4909,7 +4909,7 @@
 
   // -fmodule-name specifies the module that is currently being built (or
   // used for header checking by -fmodule-maps).
-  Args.AddLastArg(CmdArgs, options::OPT_fmodule_name);
+  Args.AddLastArg(CmdArgs, options::OPT_fmodule_name_EQ);
 
   // -fmodule-map-file can be used to specify files containing module
   // definitions.