[clang] [clang][MBD] set up module build daemon infrastructure (PR #67562)

[Michael Spencer via cfe-commits]

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@@ -0,0 +1,18 @@
+// Check that clang invocation can spawn and handshake with module build daemon
+
+// REQUIRES: !system-windows
+
+//  RUN: if pgrep -f "cc1modbuildd mbd-handshake"; then pkill -f "cc1modbuildd mbd-handshake"; fi
+//  RUN: rm -rf mbd-handshake %t
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Bigcheese wrote:

`mbd-handshake` should be `%t/mbd-handshake` in these tests.

https://github.com/llvm/llvm-project/pull/67562