* c-common.c (c_common_init): Set CPP arithmetic precision.
	* cppexp.c (cpp_num_part): Move typedef ...
	* cpphash.h: ...here; make unsigned HOST_WIDE_INT.
	* cppinit.c (cpp_create_reader): Default to host long arithmetic.
	(sanity_checks): Update.
testsuite:
	* gcc.dg/cpp/arith-2.c, gcc.dg/cpp/arith-3.c: New tests.
	* gcc.dg/cpp/if-3.c: Remove.

From-SVN: r53911