Match: Refactor unsigned SAT_MUL form 1 mul and widen-mul by for [NFC]

Match: Refactor unsigned SAT_MUL form 1 mul and widen-mul by for [NFC]

Inspired by the previous patch, the form 1 of unsigned SAT_MUL
can be mul or widen-mul based.  So we can leverage the keyword
for to group it, and avoid the pattern duplication.

The below test suites are passed for this patch:
1. The rv64gcv fully regression tests.
2. The x86 bootstrap tests.
3. The x86 fully regression tests.

gcc/ChangeLog:

	* match.pd: Refactor the form 1 of SAT_MUL by keyword for.

Signed-off-by: Pan Li <pan2.li@intel.com>