fix: support 'L', 'LL', 'UL' suffix in integer literals & correct float negation in WAT generator

[morpheuschoo]

Fix:

• suffixes ll, l, ul, and their uppercase equivalents were not recognised. This PR fixes this.
• fixes the floating-point negation in the WAT generator.

[uylulu]

Looks good!

[benmurphyy]

Thanks, perhaps add some tests verifying exactly what you fixed in ctowasm/test/samples? You can create a new folder for it, or use subset4 since thats where floats were first introduced, just remember to add the entry for each test in ctowasm/test/testLog.js