[clang] [Clang] Separate implicit int conversion on negation sign to new diagnostic group (PR #139429)

[Aaron Ballman via cfe-commits]

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@@ -0,0 +1,64 @@
+// RUN: %clang_cc1 %s -verify -Wimplicit-int-conversion
+// RUN: %clang_cc1 %s -verify -Wimplicit-int-conversion -Wno-implicit-int-conversion-on-negation -DNO_DIAG
+
+char test_char(char x) {
+  return -x;
+#ifndef NO_DIAG
+  // expected-warning at -2 {{implicit conversion loses integer precision}}
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AaronBallman wrote:

Is this actually checking for the new diagnostic ("on negation")? If so, you should update the expected warning to include the whole diagnostic text.

https://github.com/llvm/llvm-project/pull/139429