Add test case

This previously produced use-after-free under asan.

Author: nikic

llvm/test/CodeGen/PowerPC/mergeable-string-pool-pr92991.ll

@@ -0,0 +1,20 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+; RUN: llc -mtriple=powerpc64le-unknown-linux-gnu < %s | FileCheck %s
+
+@g = private constant [4 x i32] [i32 122, i32 67, i32 35, i32 56]
+@g2 = private constant [1 x i64] [i64 1], align 8
+
+define void @test(ptr %p, ptr %p2) {
+; CHECK-LABEL: test:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    addis 5, 2, .L__ModuleStringPool@toc@ha
+; CHECK-NEXT:    addi 5, 5, .L__ModuleStringPool@toc@l
+; CHECK-NEXT:    addi 6, 5, 12
+; CHECK-NEXT:    std 6, 0(3)
+; CHECK-NEXT:    addi 3, 5, 16
+; CHECK-NEXT:    std 3, 0(4)
+; CHECK-NEXT:    blr
+  store ptr getelementptr inbounds ([4 x i32], ptr @g, i64 0, i64 1), ptr %p
+  store ptr getelementptr inbounds ([4 x i32], ptr @g, i64 0, i64 2), ptr %p2
+  ret void
+}