To view the non-whitespace changes in this CL:

  git cl patch -b testbranch 1678133003
  git diff -w --ignore-blank-lines -b master

Such changes are only in gen_arm32_reg_tables.py and IceInst.cpp.

There are lots of tab characters in .ll files that shouldn't be there, but fixing them would require some thought about how to do consistent formatting, so that's left for later.

BUG= none
R=eholk@chromium.org, kschimpf@google.com

Review URL: https://codereview.chromium.org/1678133003 .