The previous implementation was charging about 24% more time that it
should to the function parser. The cause was that the time to "queue" the
parsed functions, and the time to emit the assembled code (again
including "queue" time) was not accounted for. About 15% was going to
queuing costs, and 7% to emitting the ELF file.

This CL adds timing of function translateFunctions, which captures most
of the queueing costs, and timing for each of the major ELF emission
functions (emitELF). This allows the corresponding costs to be better
bucketed, and not charged to the time it takes to parse functions in
bitcode files.

Bug=None

R=jpp@chromium.org, stichnot@chromium.org

Review URL: https://codereview.chromium.org/1775603002 .