[llvm] Loosen DWARF form check in discriminant-member.ll (PR #139258)

[Hubert Tong via llvm-commits]

================
@@ -5,14 +5,14 @@
 ; of discriminants, and where both refer to a DIE that is not a child
 ; of the variant.
 
-; CHECK: DW_AT_name [DW_FORM_strp]  ({{.*}} = "Discr")
+; CHECK: DW_AT_name [DW_FORM_str{{[a-z]+}}]  ({{.*}} = "Discr")
----------------
hubert-reinterpretcast wrote:

```suggestion
; CHECK: DW_AT_name [DW_FORM_str{{[a-z]+}}]  ({{(.* = )?}}"Discr")
```

https://github.com/llvm/llvm-project/pull/139258