Change SPIRVInstTemplate creation order

In a followup commit, an instruction's required capabilities will
depend on its argument types.  This does not work with the current
LLVM-to-SPIR-V translation that consists of the following steps:
 1. Create the instruction without operands.
 2. Add it to the module (which queries the instruction's required
    capabilities).
 3. Add operands.

Swap steps 2 and 3, such that the instruction is fully constructed
before querying its required capabilities.

Original commit:
KhronosGroup/SPIRV-LLVM-Translator@adc930c

Author: svenvh

llvm-spirv/lib/SPIRV/SPIRVWriter.cpp

@@ -4125,7 +4125,7 @@ LLVMToSPIRVBase::transBuiltinToInstWithoutDecoration(Op OC, CallInst *CI,
         SPRetTy = transType(F->arg_begin()->getType()->getPointerElementType());
         Args.erase(Args.begin());
       }
-      auto SPI = BM->addInstTemplate(OC, BB, SPRetTy);
+      auto *SPI = SPIRVInstTemplateBase::create(OC);
       std::vector<SPIRVWord> SPArgs;
       for (size_t I = 0, E = Args.size(); I != E; ++I) {
         assert((!isFunctionPointerType(Args[I]->getType()) ||
@@ -4135,7 +4135,7 @@ LLVMToSPIRVBase::transBuiltinToInstWithoutDecoration(Op OC, CallInst *CI,
                              ? cast<ConstantInt>(Args[I])->getZExtValue()
                              : transValue(Args[I], BB)->getId());
       }
-      SPI->setOpWordsAndValidate(SPArgs);
+      BM->addInstTemplate(SPI, SPArgs, BB, SPRetTy);
       if (!SPRetTy || !SPRetTy->isTypeStruct())
         return SPI;
       std::vector<SPIRVWord> Mem;

llvm-spirv/lib/SPIRV/libSPIRV/SPIRVModule.cpp

@@ -359,6 +359,9 @@ class SPIRVModuleImpl : public SPIRVModule {
                                          const std::vector<SPIRVWord> &Ops,
                                          SPIRVBasicBlock *BB,
                                          SPIRVType *Ty) override;
+  void addInstTemplate(SPIRVInstTemplateBase *Ins,
+                       const std::vector<SPIRVWord> &Ops, SPIRVBasicBlock *BB,
+                       SPIRVType *Ty) override;
   SPIRVInstruction *addLifetimeInst(Op OC, SPIRVValue *Object, SPIRVWord Size,
                                     SPIRVBasicBlock *BB) override;
   SPIRVInstruction *addMemoryBarrierInst(Scope ScopeKind, SPIRVWord MemFlag,
@@ -2071,6 +2074,16 @@ SPIRVModuleImpl::addInstTemplate(Op OC, const std::vector<SPIRVWord> &Ops,
   return Ins;
 }
 
+void SPIRVModuleImpl::addInstTemplate(SPIRVInstTemplateBase *Ins,
+                                      const std::vector<SPIRVWord> &Ops,
+                                      SPIRVBasicBlock *BB, SPIRVType *Ty) {
+  assert(!Ty || !Ty->isTypeVoid());
+  SPIRVId Id = Ty ? getId() : SPIRVID_INVALID;
+  Ins->init(Ty, Id, BB, this);
+  Ins->setOpWordsAndValidate(Ops);
+  BB->addInstruction(Ins);
+}
+
 SPIRVId SPIRVModuleImpl::getExtInstSetId(SPIRVExtInstSetKind Kind) const {
   assert(Kind < SPIRVEIS_Count && "Unknown extended instruction set!");
   auto Res = ExtInstSetIds.find(Kind);

llvm-spirv/lib/SPIRV/libSPIRV/SPIRVModule.h

@@ -360,6 +360,9 @@ class SPIRVModule {
   virtual SPIRVInstTemplateBase *
   addInstTemplate(Op OC, const std::vector<SPIRVWord> &Ops, SPIRVBasicBlock *BB,
                   SPIRVType *Ty) = 0;
+  virtual void addInstTemplate(SPIRVInstTemplateBase *Ins,
+                               const std::vector<SPIRVWord> &Ops,
+                               SPIRVBasicBlock *BB, SPIRVType *Ty) = 0;
   virtual SPIRVInstruction *addLoadInst(SPIRVValue *,
                                         const std::vector<SPIRVWord> &,
                                         SPIRVBasicBlock *) = 0;