Revert "[AArch64][SME] Disable GlobalISel/FastISel for SME functions."

Reverting the patch due to a buildbot failure.

This reverts commit e1e260c.

llvm/lib/Target/AArch64/AArch64FastISel.cpp

@@ -5032,8 +5032,6 @@ bool AArch64FastISel::selectAtomicCmpXchg(const AtomicCmpXchgInst *I) {
 }
 
 bool AArch64FastISel::fastSelectInstruction(const Instruction *I) {
-  if (TLI.fallBackToDAGISel(*I))
-    return false;
   switch (I->getOpcode()) {
   default:
     break;
@@ -5116,10 +5114,5 @@ bool AArch64FastISel::fastSelectInstruction(const Instruction *I) {
 
 FastISel *AArch64::createFastISel(FunctionLoweringInfo &FuncInfo,
                                         const TargetLibraryInfo *LibInfo) {
-
-  SMEAttrs CallerAttrs(*FuncInfo.Fn);
-  if (CallerAttrs.hasZAState() ||
-      (!CallerAttrs.hasStreamingInterface() && CallerAttrs.hasStreamingBody()))
-    return nullptr;
   return new AArch64FastISel(FuncInfo, LibInfo);
 }

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

@@ -22054,15 +22054,6 @@ bool AArch64TargetLowering::fallBackToDAGISel(const Instruction &Inst) const {
       return true;
   }
 
-  // Checks to allow the use of SME instructions
-  if (auto *Base = dyn_cast<CallBase>(&Inst)) {
-    auto CallerAttrs = SMEAttrs(*Inst.getFunction());
-    auto CalleeAttrs = SMEAttrs(*Base);
-    if (CallerAttrs.requiresSMChange(CalleeAttrs,
-                                     /*BodyOverridesInterface=*/false) ||
-        CallerAttrs.requiresLazySave(CalleeAttrs))
-      return true;
-  }
   return false;
 }
 

llvm/lib/Target/AArch64/GISel/AArch64CallLowering.cpp

@@ -537,12 +537,6 @@ bool AArch64CallLowering::fallBackToDAGISel(const MachineFunction &MF) const {
     LLVM_DEBUG(dbgs() << "Falling back to SDAG because we don't support no-NEON\n");
     return true;
   }
-
-  SMEAttrs Attrs(F);
-  if (Attrs.hasNewZAInterface() ||
-      (!Attrs.hasStreamingInterface() && Attrs.hasStreamingBody()))
-    return true;
-
   return false;
 }