PR tree-ssa/54295
	* tree-ssa-math-opts.c (widening_mult_conversion_strippable_p):
	Sign-extension of a zero-extended value can be simplified to
	just zero-extension.

testsuite:
	* gcc.target/arm/pr50318-1.c: Scan for smlal.
	* gcc.target/arm/smlaltb-1.c: XFAIL test.
	* gcc.target/arm/smlaltt-1.c: Likewise.

From-SVN: r191066