PATCH GAS numbers with radix in suffix

[Timothy Wall]

This patch allows GAS to properly parse constants with the suffix in the
radix, e.g.

0101001b (binary)
0FFFEh (hex)
0774Q (octal)

* gas/doc/internals.texi: Document NUMBERS_WITH_SUFFIX option.
* gas/as.h: Provide a default NUMBERS_WITH_SUFFIX definition (zero).
* gas/expr.c: Handle numbers with suffixes if NUMBERS_WITH_SUFFIX is
non-zero.