Merge commit 354d3106c from llvm git (by Kai Luo):

Merge commit 354d3106c from llvm git (by Kai Luo):

  [PowerPC] Skip combining (uint_to_fp x) if x is not simple type

  Current powerpc64le backend hits
  ```
  Combining: t7: f64 = uint_to_fp t6
  llc: llvm-project/llvm/include/llvm/CodeGen/ValueTypes.h:291:
  llvm::MVT llvm::EVT::getSimpleVT() const: Assertion `isSimple() &&
  "Expected a SimpleValueType!"' failed.
  ```
  This patch fixes it by skipping combination if `t6` is not simple
  type.
  Fixed https://bugs.llvm.org/show_bug.cgi?id=47660.

  Reviewed By: #powerpc, steven.zhang

  Differential Revision: https://reviews.llvm.org/D88388

This should fix the llvm assertion mentioned above when building the
following ports for powerpc64le:

* audio/traverso
* databases/percona57-pam-for-mysql
* databases/percona57-server
* emulators/citra
* emulators/citra-qt5
* games/7kaa
* graphics/dia
* graphics/mandelbulber
* graphics/pcl-pointclouds
* net-p2p/libtorrent-rasterbar
* textproc/htmldoc

Requested by:	pkubaj
MFC after:	3 days