libgccjit: Fix a bootstrap break for some targets.

libgccjit: Fix a bootstrap break for some targets.

Some targets use 'long long unsigned int' for unsigned HW int, and this
leads to a Werror=format= fail for two print cases in jit-playback.cc
introduced in r12-8117-g30f7c83e9cfe (Add support for bitcasts [PR104071])

As discussed on IRC, casting to (long) seems entirely reasonable for the
values (since they are type sizes).

tested that this fixes bootstrap on x86_64-darwin19 and running check-jit.

Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>
gcc/jit/ChangeLog:

	* jit-playback.cc (new_bitcast): Cast values returned by tree_to_uhwi
	to 'long' to match the print format.