Clean up and fix asserts.

Author: s-perron

tools/clang/include/clang/SPIRV/SpirvBuilder.h

@@ -997,9 +997,6 @@ SpirvInstruction *SpirvBuilder::addExecutionModeId(
   SpirvExecutionModeId *mode = nullptr;
   SpirvExecutionModeBase *existingInstruction =
       mod->findExecutionMode(entryPoint, em);
-  assert(!existingInstruction || existingInstruction->getKind() ==
-                                     SpirvInstruction::IK_ExecutionModeId);
-
   if (!existingInstruction) {
     mode = new (context) SpirvExecutionModeId(loc, entryPoint, em, params);
     mod->addExecutionMode(mode);
@@ -1009,7 +1006,7 @@ SpirvInstruction *SpirvBuilder::addExecutionModeId(
     // `addExecutionMode` should have been called with `em` or the existing
     // instruction is wrong.
     assert(existingInstruction->getKind() ==
-           SpirvInstruction::IK_ExecutionMode);
+           SpirvInstruction::IK_ExecutionModeId);
     mode = cast<SpirvExecutionModeId>(existingInstruction);
   }
 

tools/clang/lib/SPIRV/EmitVisitor.cpp

@@ -628,8 +628,7 @@ bool EmitVisitor::visit(SpirvExecutionModeBase *inst) {
       curInst.push_back(getOrAssignResultId<SpirvInstruction>(param));
     }
   } else {
-    auto *exeMode = dyn_cast<SpirvExecutionMode>(inst);
-    assert(exeMode);
+    auto *exeMode = llvm::cast<SpirvExecutionMode>(inst);
     ArrayRef<uint32_t> params = exeMode->getParams();
     curInst.insert(curInst.end(), params.begin(), params.end());
   }