Fix hash_integer_value
Fix hash_integer_value

Broken in D18938 because underlying_type only works for enums and not all stdlibs are sad when given a non-enum. Bots error out with 'only enumeration types have underlying types'.

There's probably a clever enable_if-ism that I can do with underlying_type and the actual integer value, but is_integral_or_enum also accepts implicit conversion so I need to ponder my life choices a bit before committing to template magic. A quick fix for now.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@265880 91177308-0d34-0410-b5e6-96231b3b80d8

GPUOpen-Drivers/llvm,llvm-mirror/llvm,apple/swift-llvm,llvm-mirror/llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,llvm-mirror/llvm,llvm-mirror/llvm,apple/swift-llvm,llvm-mirror/llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm