Subzero: Improve the output with the --timing-focus=xxx option.

Subzero: Improve the output with the --timing-focus=xxx option.

Makes sure the percentages represent only the function(s) focused on, and not with respect to the total translation time across all functions.

Reset the timings between functions so that --timing-focus=* gives reasonable numbers.

Also, adds a timer for the live range construction phase.

BUG= none
R=jvoung@chromium.org

Committed: https://gerrit.chromium.org/gerrit/gitweb?p=native_client/pnacl-subzero.git;a=commit;h=d14b1a027a88e1f54845fa5970c0bb462e01fcd4

[Jim Stichnoth, 2014-10-08 14:07:56]

stichnot@chromium.org changed reviewers:
+ jvoung@chromium.org

[jvoung (off chromium), 2014-10-08 15:08:41]

lgtm

[Jim Stichnoth, 2014-10-08 15:28:47]

Committed patchset #2 (id:20001) manually as
d14b1a027a88e1f54845fa5970c0bb462e01fcd4 (tree was closed).