Re-commit "Modernize NativeProcessProtocol::GetSoftwareBreakpointTrapOpcode"

This recommits r341487, which was reverted due to failing tests with
clang. It turned out I had incorrectly expected that the literal arrays
passed to ArrayRef constructor will have static (permanent) storage.
This was only the case with gcc, while clang was constructing them on
stack, leading to dangling pointers when the function returns.

The fix is to explicitly assign static storage duration to the opcode
arrays.

llvm-svn: 341758