* Remove Impl struct in Reducer; we can re-add it later (in a cleaner fashion) if we need to.
* Add cleanup passes in Reducer; needed so that removal of constants can be disabled during the main passes, and then enabled during cleanup passes, otherwise some main passes can perform worse due to lack of available constants.
* Delete passes: remove op name, remove relaxed precision. And delete associated tests.
* Add more tests for remove unreferenced instructions.
* Always return and write the output file, even if there was a reduction failure.
* Only exit with 0 if the reduction completed or we hit the reduction step limit.
Adds a reduction pass that removes OpDecorate and OpMemberDecorate
instructions that annotate instructions and members with
RelaxedPrecision. As well as being useful in its own right, removing
such references allows other passes to remove further instructions.
* Fix#2320. `conditional_branch_to_simple_conditional_branch` reduction pass changes conditional branches so both targets point to the same block id (creating a "simple" conditional branch).
* Fix#2501. `simple_conditional_branch_to_branch` reduction pass changes "simple" conditional branches to branches.
* Fix#2503. `conditional_branch_to_simple_conditional_branch` proper handling of back-edges.
* Fixes#2358. Added to the reducer the ability to remove a function that is not directly called. Factored out some code from the optimizer to help with this.
Fixes#2120
Enhanced the reducer so that it can merge blocks together, leveraging the functionality extracted from the block_merge pass in the optimizer.
* Add OperandToUndefReductionPass.
Fixes#2115.
Also added some tests that are similar to those in OperandToConstantReductionPassTest.
In addition, refactor FindOrCreateGlobalUndef into reduction_util.cpp. Fixes#2184.
Removed many documentation comments that were identical or very similar to the overridden function's documentation comment.
* Run validator during reduction.
* Added functionality to validate modules after each reduction step, and some tests to check this is working. Also fixed an issue where reduction passes were not guaranteed to be executed at their minimum granularities.
Add a spirv-reduce pass which removes OpName and OpMemberName instructions.
This is useful to enable other reduction passes, e.g. RemoveUnreferencedInstruction may not be able to remove an instruction creating an id whose only usage is an OpName for this id.
* Added a reduction pass to replace ids with ids of the same type that dominate them.
* Introduce helper method for querying whether an operand type is an input id.
