AArch64: Add arm64ec libcall tests for __arm_sc_* functions (#144356)

Author: arsenm

llvm/test/CodeGen/AArch64/arm64ec-builtins.ll

@@ -42,3 +42,33 @@ define float @f6(float %val, i32 %a) {
   %call = tail call fast float @llvm.ldexp.f32(float %val, i32 %a)
   ret float %call
 }
+
+@dst = global [512 x i8] zeroinitializer, align 1
+@src = global [512 x i8] zeroinitializer, align 1
+
+; FIXME: Wrong and probably needs a # prefix
+define void @call__arm_sc_memcpy(i64 noundef %n) #0 {
+; CHECK-LABEL: "#call__arm_sc_memcpy":
+; CHECK: bl __arm_sc_memcpy
+
+  tail call void @llvm.memcpy.p0.p0.i64(ptr align 1 @dst, ptr nonnull align 1 @src, i64 %n, i1 false)
+  ret void
+}
+
+; FIXME: Wrong and probably needs a # prefix
+define void @call__arm_sc_memmove(i64 noundef %n) #0 {
+; CHECK-LABEL: "#call__arm_sc_memmove":
+; CHECK: bl __arm_sc_memmove
+  tail call void @llvm.memmove.p0.p0.i64(ptr align 1 @dst, ptr nonnull align 1 @src, i64 %n, i1 false)
+  ret void
+}
+
+; FIXME: Wrong and probably needs a # prefix
+define void @call__arm_sc_memset(i64 noundef %n) #0 {
+; CHECK-LABEL: "#call__arm_sc_memset":
+; CHECK: bl __arm_sc_memset
+  tail call void @llvm.memset.p0.i64(ptr align 1 @dst, i8 2, i64 %n, i1 false)
+  ret void
+}
+
+attributes #0 = { nounwind "aarch64_pstate_sm_enabled" "target-features"="+sme2" }