[llvm][HWASan] Replace calls to Type::getPointerTo (NFC)

If `Type::getPointerTo` is called solely to support an unnecessary
pointer-cast, remove the call entirely.

Otherwise, replace with IRB.getPtrTy().

Clean-up work towards removing method `Type::getPointerTo`.

llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp

@@ -1217,10 +1217,8 @@ Value *HWAddressSanitizer::getHwasanThreadSlotPtr(IRBuilder<> &IRB, Type *Ty) {
     // in Bionic's libc/private/bionic_tls.h.
     Function *ThreadPointerFunc =
         Intrinsic::getDeclaration(M, Intrinsic::thread_pointer);
-    Value *SlotPtr = IRB.CreatePointerCast(
-        IRB.CreateConstGEP1_32(Int8Ty, IRB.CreateCall(ThreadPointerFunc), 0x30),
-        Ty->getPointerTo(0));
-    return SlotPtr;
+    return IRB.CreateConstGEP1_32(Int8Ty, IRB.CreateCall(ThreadPointerFunc),
+                                  0x30);
   }
   if (ThreadPtrGlobal)
     return ThreadPtrGlobal;
@@ -1305,8 +1303,8 @@ void HWAddressSanitizer::emitPrologue(IRBuilder<> &IRB, bool WithFrameRecord) {
 
       // Store data to ring buffer.
       Value *FrameRecordInfo = getFrameRecordInfo(IRB);
-      Value *RecordPtr = IRB.CreateIntToPtr(ThreadLongMaybeUntagged,
-                                            IntptrTy->getPointerTo(0));
+      Value *RecordPtr =
+          IRB.CreateIntToPtr(ThreadLongMaybeUntagged, IRB.getPtrTy(0));
       IRB.CreateStore(FrameRecordInfo, RecordPtr);
 
       // Update the ring buffer. Top byte of ThreadLong defines the size of the