AsmParser: More generic support for integer type suffices.

For integer constants, allow 'L', 'UL' as well as 'ULL' and 'LL'. This provides
better support for shared headers between .s and .c files that define bunches
of constant values.

rdar://9321056

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176118 91177308-0d34-0410-b5e6-96231b3b80d8