testsuite: Fix _BitInt in gcc.misc-tests/godump-1.c

testsuite: Fix _BitInt in gcc.misc-tests/godump-1.c

Currently _BitInt is only supported on x86_64 which means that for other
targets all tests fail with e.g.

gcc.misc-tests/godump-1.c:237:1: sorry, unimplemented: '_BitInt(32)' is not supported on this target
  237 | _BitInt(32) b32_v;
      | ^~~~~~~

Instead of requiring _BitInt support for godump-1.c, move _BitInt tests
into godump-2.c such that all other tests in godump-1.c are still
executed in case of missing _BitInt support.

gcc/testsuite/ChangeLog:

	* gcc.misc-tests/godump-1.c: Move _BitInt tests into godump-2.c.
	* gcc.misc-tests/godump-2.c: New test.