Minor improvements to 458-checker-instruction-simplification.

This follows earlier comments from Roland:
https://android-review.googlesource.com/#/c/140446
  /2/test/458-checker-instruction-simplification/src/Main.java@337
  /2/test/458-checker-instruction-simplification/src/Main.java@465

Change-Id: I255ab74b8885dd8e86bb2c11bba4075fa0eaa183
3 files changed