[GlobalISel][IRTranslator] Ignore the llvm.experimental.noalias.scope.decl intrinsic.

These don't generate any code.

Author: aemerson

llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp

@@ -2126,6 +2126,7 @@ bool IRTranslator::translateKnownIntrinsic(const CallInst &CI, Intrinsic::ID ID,
     return true;
   }
   case Intrinsic::assume:
+  case Intrinsic::experimental_noalias_scope_decl:
   case Intrinsic::var_annotation:
   case Intrinsic::sideeffect:
     // Discard annotate attributes, assumptions, and artificial side-effects.

llvm/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll

@@ -2388,6 +2388,20 @@ define void @test_assume(i1 %x) {
   ret void
 }
 
+declare void @llvm.experimental.noalias.scope.decl(metadata)
+define void @test.llvm.noalias.scope.decl(i8* %P, i8* %Q) nounwind ssp {
+  tail call void @llvm.experimental.noalias.scope.decl(metadata !3)
+  ; CHECK-LABEL: name: test.llvm.noalias.scope.decl
+  ; CHECK-NOT: llvm.experimental.noalias.scope.decl
+  ; CHECK: RET_ReallyLR
+  ret void
+}
+
+!3 = !{ !4 }
+!4 = distinct !{ !4, !5, !"test1: var" }
+!5 = distinct !{ !5, !"test1" }
+
+
 declare void @llvm.sideeffect()
 define void @test_sideeffect() {
   ; CHECK-LABEL: name:            test_sideeffect