For the print_stacktrace(thread, string_buffer = False) function, if we have debug info
  for a frame function, let's also emit the args for the current function.

o TestFrameUtils.py:

  Add stronger assertTrue for frame0's args.

o TestPrintStackTraces.py:

  Launch the inferior with ["abc", "xyz"] and expect '(int)argc=3' in the stack traces, since
  by design the inferior is built with debug info.

llvm-svn: 133204