Since the VSrc_* register classes contain both VGPRs and SGPRs, copies
that used be emitted by isel like this:
SGPR = COPY VGPR
Will now be emitted like this:
VSrC = COPY VGPR
This patch also adds a pass that tries to identify and fix situations where
a VGPR to SGPR copy may occur. Hopefully, these changes will make it
impossible for the compiler to generate illegal VGPR to SGPR copies.
llvm-svn: 187831
3b9645302a