Group mterp files

Group hundreds of tiny files into larger files
(but still less than 1000 lines of code each).
This should make editing and reviews simpler.

This CL is just simple file concatenation.
The filenames don't have any meaning any more.

The generated assembly output is still the same.

Test: test-art-host-gtest
Change-Id: Iee493f334999c2e06a72e19d3c065d19c67323f1
1810 files changed