Assembler::testw(Register, Immediate) and Assembler::testw(const Operand&, Immediate) were emitting only the first 8 bits of a 16-bit immediate, causing unexpected crashes.

This went unnoticed because before http://crrev.com/1948453002 no compiler was using them.

Review-Url: https://codereview.chromium.org/1962563003
Cr-Commit-Position: refs/heads/master@{#36110}