Add an accessor for IRInst opcode (#1707)

* Add an accessor for IRInst opcode

This main changing is renaming `IRInst::op` over to `IRInst::m_op` and then adds an accessor `IRInst::getOp()` to read it. The rest of the changes are just changing use sites to `getOp` (or to `m_op` in the limited cases where we write to it).

This work is in anticipation of a future change that might need to store an extra bit in the same field as the opcode. It seemed better to do this massive refactoring as a separate PR.

* fixup

1 files changed, 1 insertions, 1 deletions

diff --git a/source/slang/slang-ir-augment-make-existential.cpp b/source/slang/slang-ir-augment-make-existential.cpp
index 18d061276..2fe820721 100644
--- a/source/slang/slang-ir-augment-make-existential.cpp
+++ b/source/slang/slang-ir-augment-make-existential.cpp
@@ -40,7 +40,7 @@ struct AugmentMakeExistentialContext
 
     void processInst(IRInst* inst)
     {
-        switch (inst->op)
+        switch (inst->getOp())
         {
         case kIROp_MakeExistential:
             processMakeExistential((IRMakeExistential*)inst);