Merging r329852:

------------------------------------------------------------------------
r329852 | nemanjai | 2018-04-11 14:25:44 -0700 (Wed, 11 Apr 2018) | 8 lines

[PowerPC] Fix condition for 64-bit rotate when replacing r+r instr with r+i

This patch fixes https://bugs.llvm.org/show_bug.cgi?id=37039
The condition only covers one of the two 64-bit rotate instructions. This just
adds the second (RLDICLo).

Patch by Josh Stone.

------------------------------------------------------------------------

llvm-svn: 330076