Refactor rate_limit.go for more clarify

This wasn't intended to change the behavior, but it does slightly.

  Previously any requests to acquire memory wouldn't block; only
  (subsequent) requests for execution would block (if another
  caller had already consumed the memory quota). Now the requests
  for memory can also also block.

It turns out in a brief test on my computer that soong_zip
runs about 10 to 20% faster with this change than without it.

  The final step involving soong_zip decreased from about
  3.6 sec to about 3.3 sec in tests on my computer.

  When testing the process of re-zipping the contents of
  angler-target_files*.zip , the time decreased from about
  6.3 sec to about 5.3 sec in tests on my computer, and the
  peak memory usage reported by `top` decreased from about
  1.5g to 1g

Bug: 64536066
Test: m -j dist showcommands # which runs soong_zip to package everything
Change-Id: I0422e4c363c675bb7a93309fac4616c768bfbe8f

0 files changed, 0 insertions, 0 deletions