This corrects a "cleanup" mistake in line 414/417 of https://codereview.chromium.org/1838753002/diff/120001/src/IceTargetLoweringX8664.cpp .
This wasn't caught before because "make presubmit" doesn't run any sandboxed x86-64 tests. So we add that to the presubmit script.
In addition, the "make check-spec" is changed to run each spec component via the "--run" flag of szbuild_spec2k.py. Otherwise, the makefile was hard-coding running the native binary setup instead of the sandboxed or nonsfi setup.
BUG= none
R=jpp@chromium.org
Review URL: https://codereview.chromium.org/1852713004 .
