[NVPTX] Make constant vector test case endian-independent

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190998 91177308-0d34-0410-b5e6-96231b3b80d8
DAGCombiner: Don't fold vector muls with constants that look like a splat of a power of 2 but differ in bit width.

PR17283.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191000 91177308-0d34-0410-b5e6-96231b3b80d8