[PATCH] clang-cl: Add support for -o

[Hans Wennborg]

LGTM, thanks for fixing

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Comment at: lib/Driver/Driver.cpp:1620
@@ +1619,3 @@
+    options::ID MaybeFe =
+        Ty == types::TY_Image ? options::OPT__SLASH_Fe : options::OPT_INVALID;
+    Arg *FinalOutput = C.getArgs().getLastArg(options::OPT_o, MaybeFA, MaybeFa,
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I wish this was simpler :/

http://reviews.llvm.org/D3771