Rename OpCode.h -> DexOpcodes.h.

Also incorporate the former contents of OpCodeNames.h. This is a small
attempt to increase naming consistency in libdex. There will be a bit
more to come, in a follow-up.

Change-Id: Ia7ab06042dde2e19eda02ef1fee72fb4260e899d
diff --git a/opcode-gen/regen-all b/opcode-gen/regen-all
index fbf8359..1e77b5d 100755
--- a/opcode-gen/regen-all
+++ b/opcode-gen/regen-all
@@ -37,8 +37,8 @@
 ${progdir}/opcode-gen dx/src/com/android/dx/dex/code/DalvOps.java
 ${progdir}/opcode-gen dx/src/com/android/dx/dex/code/Dops.java
 ${progdir}/opcode-gen dx/src/com/android/dx/dex/code/RopToDop.java
+${progdir}/opcode-gen libdex/DexOpcodes.h
 ${progdir}/opcode-gen libdex/InstrUtils.c
-${progdir}/opcode-gen libdex/OpCode.h
 ${progdir}/opcode-gen libdex/OpCodeNames.c
 
 # It's a minor shame that these files live in a different top-level project.