[KeyInstr][Clang][NFC] Add test for array cookie store (#146517)

It doesn't need to be a Key Instruction.

Author: OCHyams

clang/test/DebugInfo/KeyInstructions/array-cookie.cpp

@@ -0,0 +1,12 @@
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -gkey-instructions %s -debug-info-kind=line-tables-only -gno-column-info -emit-llvm -o - \
+// RUN: | FileCheck %s
+
+// Array cookie store doesn't need to be a key instruction.
+
+struct a { char c; ~a(); };
+void b() { new a[2]; }
+
+// CHECK:      %call = call {{.*}}ptr @_Znam(i64 noundef 10)
+// CHECK-NEXT: store i64 2, ptr %call, align 8, !dbg [[DBG:!.*]]
+
+// CHECK: [[DBG]] = !DILocation(line: 7, scope: ![[#]])