iorap: merge consecutive entries in compiled trace

This will reduce the size of compiled trace and the delay for
prefetching.

The benchmarking shows it will improve the startup by ~1.2%
https://dashboards.corp.google.com/_f31ff276_6cb2_4ed6_973b_9640c4fb0df4?fb=BootImageProfileId:eq:2950

Bug: 174373409
Test: Run compilation and compare the compiled trace with before.

Change-Id: Ieff8162dd19b193b3da225cf4c8edeaa9238c75d
1 file changed