This CL moves the files in opt/ to consistenly be under the opt::
namespace. This frees up the ir:: namespace so it can be used to make a
shared ir represenation.
Re-formatted the source tree with the command:
$ /usr/bin/clang-format -style=file -i \
$(find include source tools test utils -name '*.cpp' -or -name '*.h')
This required a fix to source/val/decoration.h. It was not including
spirv.h, which broke builds when the #include headers were re-ordered by
clang-format.
