remove need for -Wno-narrowing

This is a default warning in GCC,
so it's kind of annoying if you just `g++ -c`.

PS1 works in GCC 7 and GCC 8, but is miscompiled by GCC 6.
PS2 seems fine in each.

(GCC 9 will also have __builtin_convertvector() like Clang.)

Change-Id: Ifcad3dd73fa30fca9663e7ebcc17701b4accd7e5
Commit-Queue: Mike Klein <>
Auto-Submit: Mike Klein <>
Reviewed-by: Brian Osman <>
2 files changed