[clang] [llvm] [driver] Make --version show if assertions, etc. are enabled (PR #87585)

[Jon Roelofs via cfe-commits]

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@@ -0,0 +1,6 @@
+# REQUIRES: asserts
+# RUN: %clang --version 2>&1 | FileCheck %s
+
+# CHECK: clang version
+# When assertions are enabled, we should have a build configuration line that reflects that
+# CHECK: Build configuration: {{.*}}+assertions
----------------
jroelofs wrote:

```suggestion
# CHECK: Build config: {{.*}}+assertions
```

https://github.com/llvm/llvm-project/pull/87585