Avoid using NanoTime for compiler and verifier

Target timings before with -j2 --compiler-filter=interpret-only:
Approximate speedup 3%.

Before:
real    0m36.852s
real    0m36.050s
real    0m36.246s

After:
real    0m35.667s
real    0m35.779s
real    0m35.458s

Bug: 16853450

Change-Id: Id996172d8283639fe293ddfc26d01fc1a0beed0b