Merging r155975:

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r155975 | rsmith | 2012-05-01 18:29:43 -0700 (Tue, 01 May 2012) | 4 lines

Disable our non-standard delayed parsing of exception specifications. Delaying
the parsing of such things appears to be a conforming extension, but it breaks
libstdc++4.7's std::pair.

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llvm-svn: 156672