Merging r245530:

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r245530 | hfinkel | 2015-08-19 18:18:20 -0700 (Wed, 19 Aug 2015) | 5 lines

[PowerPC] Fix the int2fp(fp2int(x)) DAGCombine to ignore ppc_fp128

This DAGCombine was creating custom SDAG nodes with an illegal ppc_fp128
operand type because it was triggering on f64/f32 int2fp(fp2int(ppc_fp128 x)),
but shouldn't (it should only apply to f32/f64 types). The result was a crash.
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llvm-svn: 245573