This patch adds the possibility to make the following constants:
* long long
* long double
* complex long double

The long long one is needed for 32bit systems.

The new entrypoints are:
gcc_jit_context_new_rvalue_from_long_long
gcc_jit_context_new_rvalue_from_long_double
gcc_jit_context_new_rvalue_from_complex_long_double

The patch also fixes a issue with the reproducer's debug 
c-file writer, which does not handle floating point numbers
very well. I.e. infs, NaN and losing precision on doubles.

make check-jit runs fine with the patch series on Debian 64x.

See attachment.