Merging r195136:
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r195136 | marshall | 2013-11-19 10:05:03 -0800 (Tue, 19 Nov 2013) | 1 line

Patch by Bruce Mitchener. Change all references to EMSCRIPTEN to __EMSCRIPTEN__. If you're not using the PP symbol EMSCRIPTEN, then you should see no functionality change.
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git-svn-id: https://llvm.org/svn/llvm-project/libcxx/branches/release_34@195622 91177308-0d34-0410-b5e6-96231b3b80d8