[llvm] [llvm][Support] fix convertToSnakeFromCamelCase (PR #68375)

[via llvm-commits]

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@@ -184,6 +184,12 @@ TEST(StringExtrasTest, ConvertToSnakeFromCamelCase) {
 
   testConvertToSnakeCase("OpName", "op_name");
   testConvertToSnakeCase("opName", "op_name");
+  testConvertToSnakeCase("OPName", "op_name");
+  testConvertToSnakeCase("Intel_OCL_BI", "intel_ocl_bi");
+  testConvertToSnakeCase("opNAME", "op_name");
+  testConvertToSnakeCase("opNAMe", "op_na_me");
+  testConvertToSnakeCase("opnameE", "opname_e");
+  testConvertToSnakeCase("OPNameOPName", "op_name_op_name");
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rkayaith wrote:

could you add a test that hits the `isdigit` check

https://github.com/llvm/llvm-project/pull/68375