The lexer was not allowing underscores between leading zeros in decimal integer
literals and float literals (e.g. 0_0 or 0_0.0).
library/lexer.m:
Allow underscores in the above cases.
tests/hard_coded/parse_number_from_io.{m,exp,exp2,exp3}:
tests/hard_coded/parse_number_from_string.{m,exp,exp2,exp3}:
Extend these tests to cover the above cases.
tests/invalid/invalid_binary_literal.err_exp:
tests/invalid/invalid_octal_literal.err_exp:
tests/invalid/invalid_hex_literal.err_exp:
Conform to the above change.
library/lexer.m:
Add a missing predicate.
tests/hard_coded/parse_number_from_io.exp[23]:
tests/hard_coded/parse_number_from_string.exp[23]:
Additional expected outputs for the Java and C# backends.
