[clang] [Clang][Driver] Create crash reproducers for IR inputs (PR #165572)

[Eli Friedman via cfe-commits]

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@@ -0,0 +1,15 @@
+// RUN: %clang -S -emit-llvm -o %t.ll %s
+// RUN: not %clang -DCRASH %s %t.ll 2>&1 | FileCheck %s
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efriedma-quic wrote:

I suspect this regression test will break in some situations; it assumes that invoking "clang" can actually link a program, which isn't the case for less common build configs.  Can we trigger this without trying to link a program?

https://github.com/llvm/llvm-project/pull/165572