util: Add a helper for faster remainders

This should be at least as fast as using fast_idiv_by_const, and has the
advantage that the precomputation is simple enough to be evaluated at
Mesa-compile time for hash tables and sets which have a fixed table of
possible divisors.

Acked-by: Eric Anholt <eric@anholt.net>
Acked-by: Jason Ekstrand <jason@jlekstrand.net>

meson.build

@@ -834,6 +834,10 @@ if cc.compiles('int foo(void) __attribute__((__noreturn__));',
                name : '__attribute__((__noreturn__))')
   pre_args += '-DHAVE_FUNC_ATTRIBUTE_NORETURN'
 endif
+if cc.compiles('__uint128_t foo(void) { return 0; }',
+               name : '__uint128_t')
+  pre_args += '-DHAVE_UINT128'
+endif
 
 # TODO: this is very incomplete
 if ['linux', 'cygwin', 'gnu'].contains(host_machine.system())