Try to detect support for the `long long' type so that ANSI-C[89] clean

Try to detect support for the `long long' type so that ANSI-C[89] clean
code will know not to try to use `long long'.
Unfortunately the GCC spec parser will not allow us to properly detect the
"iso9899:1990" and "iso9899:199409" forms of the acceptable -std= arguments,
because of the ':' in the -std argument.  :-(  I have left them in the spec
as a place holder in hopes someone knows a way to make the detection of
them work.

Desired by:	wollman