Merging r213896:

Merging r213896:
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r213896 | compnerd | 2014-07-24 15:09:06 -0700 (Thu, 24 Jul 2014) | 6 lines

Target: invert condition for Windows

The Microsoft ABI and MSVCRT are considered the canonical C runtime and ABI.
The long double routines are not part of this environment.  However, cygwin and
MinGW both provide supplementary implementations.  Change the condition to
reflect this reality.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_35@214687 91177308-0d34-0410-b5e6-96231b3b80d8