Add libcc1 v1 compatibility to C compile feature

Add libcc1 v1 compatibility to C compile feature

This patch adds v1 compatibiltiy to the C compile feature.  The only change
in v1 concerns the handling of integer types, which permits GDB to specify
the built-in name for the type.

As far as I know, the C frontend is still on v0, so this patch is purely
precautionary. [By default C++ compile uses the equivalent of the C
frontend's int_type and float_type (aka the "v1" versions).]

gdb/ChangeLog:

	* compile/compile-c-types.c (convert_int, convert_float):
	Update for C FE v1.