[llvm] [LLVM] Change error messages to start with lower case (PR #113748)

[Matt Arsenault via llvm-commits]

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@@ -60,8 +60,8 @@ uint64_t LLLexer::atoull(const char *Buffer, const char *End) {
     uint64_t OldRes = Result;
     Result *= 10;
     Result += *Buffer-'0';
-    if (Result < OldRes) {  // Uh, oh, overflow detected!!!
-      LexError("constant bigger than 64 bits detected!");
+    if (Result < OldRes) { // overflow detected.
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arsenm wrote:

Not an error message 

https://github.com/llvm/llvm-project/pull/113748