This PR massively reorganizes the Test dialect's source files. It moves
manually-written op hooks into `TestOpDefs.cpp`, moves format custom
directive parsers and printers into `TestFormatUtils`, adds missing
comment blocks, and moves around where generated source files are
included for types, attributes, enums, etc. into their own source file.
This will hopefully help navigate the test dialect source code, but also
speeds up compile time of the test dialect by putting generated source
files into separate compilation units.
This also sets up the test dialect to shard its op definitions, done in
the next PR.
The utility functions takes a region and makes it isolated from above
by appending to the entry block arguments that represent the captured
values and replacing all uses of the captured values within the region
with the newly added arguments. The captures values are returned.
The utility function also takes an optional callback that allows
cloning operations that define the captured values into the region
during the process of making it isolated from above. The cloned value
is no longer a captured values. The operands of the operation are then
captured values. This is done transitively allow cloning of a DAG of
operations into the region based on the callback.
Reviewed By: jpienaar
Differential Revision: https://reviews.llvm.org/D148684
