[AArch64][SME] Fix frame lowering not using a base pointer for SME functions.

The existing code is checking for the presence of the +sve subtarget feature
when deciding to use a base pointer for the function, but this check doesn't
work when only +sme is used.

rdar://126878490

Author: aemerson

llvm/lib/Target/AArch64/AArch64RegisterInfo.cpp

@@ -552,7 +552,9 @@ bool AArch64RegisterInfo::hasBasePointer(const MachineFunction &MF) const {
     if (hasStackRealignment(MF))
       return true;
 
-    if (MF.getSubtarget<AArch64Subtarget>().hasSVE()) {
+    auto &ST = MF.getSubtarget<AArch64Subtarget>();
+    if (ST.hasSVE() ||
+        (ST.hasSME() && ST.hasStreamingInterfaceOrBody(MF.getFunction()))) {
       const AArch64FunctionInfo *AFI = MF.getInfo<AArch64FunctionInfo>();
       // Frames that have variable sized objects and scalable SVE objects,
       // should always use a basepointer.

llvm/lib/Target/AArch64/AArch64Subtarget.h

@@ -353,6 +353,10 @@ class AArch64Subtarget final : public AArch64GenSubtargetInfo {
   bool hasSVEorSME() const { return hasSVE() || hasSME(); }
   bool hasSVE2orSME() const { return hasSVE2() || hasSME(); }
 
+  bool hasStreamingInterfaceOrBody(const Function &F) const {
+    return SMEAttrs(F).hasStreamingInterfaceOrBody();
+  }
+
   // Return the known range for the bit length of SVE data registers. A value
   // of 0 means nothing is known about that particular limit beyong what's
   // implied by the architecture.