Rewrite kMirOpSelect for all IF_ccZ opcodes.

Also improve special cases for ARM and add tests.

Change-Id: I06f575b9c7b547dbc431dbfadf2b927151fe16b9
diff --git a/test/083-compiler-regressions/expected.txt b/test/083-compiler-regressions/expected.txt
index 541f0f8..ddd11f3 100644
--- a/test/083-compiler-regressions/expected.txt
+++ b/test/083-compiler-regressions/expected.txt
@@ -14,3 +14,4 @@
 LVNTests.testNPE2 passes
 longDivTest passes
 longModTest passes
+testIfCcz passes