Merging r251930:

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r251930 | martellmalone | 2015-11-03 10:57:45 -0500 (Tue, 03 Nov 2015) | 6 lines

Remove some legacy mingw-w64 gcc struct info

As of gcc 4.7 mingw-w64 no longer emits 128-bit structs as i128

Differential Revision: http://reviews.llvm.org/D14179

llvm-svn: 252844