[llvm] [Flang-rt][build] fixes building warnings under gcc: (PR #173955)

[liao jun via llvm-commits]

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@@ -159,7 +159,7 @@ template <typename CHAR, bool ADJUSTR>
 static RT_API_ATTRS void AdjustLRHelper(Descriptor &result,
     const Descriptor &string, const Terminator &terminator) {
   int rank{string.rank()};
-  SubscriptValue ub[maxRank], stringAt[maxRank];
+  SubscriptValue ub[maxRank]{}, stringAt[maxRank];
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zjlcd wrote:

According to context, when the `rank` is 0, `ub`  maybe not be initialized

https://github.com/llvm/llvm-project/pull/173955