Remove extraneous parens and extraneous const cast (and fix the
prototype for the function to patch what we were returning).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211837 91177308-0d34-0410-b5e6-96231b3b80d8
Remove commented out code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211838 91177308-0d34-0410-b5e6-96231b3b80d8
Remove comment that duplicated information in the constructor
that it's after.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211839 91177308-0d34-0410-b5e6-96231b3b80d8
Remove caching of the target machine in NVPTXInstrInfo and
update constructor accordingly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211840 91177308-0d34-0410-b5e6-96231b3b80d8