[clang] [clang-tools-extra] [llvm] [polly] [Unittest][Cygwin] Set $PATH when running unittests (PR #163947)

[Tomohiro Kashiwada via cfe-commits]

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@@ -19,12 +19,12 @@
 
 if platform.system() == "Darwin":
     shlibpath_var = "DYLD_LIBRARY_PATH"
-elif platform.system() == "Windows":
+elif platform.system() == "Windows" or sys.platform == "cygwin":
     shlibpath_var = "PATH"
 else:
     shlibpath_var = "LD_LIBRARY_PATH"
 config.environment[shlibpath_var] = os.path.pathsep.join(
-    ("@SHLIBDIR@", "@LLVM_LIBS_DIR@", config.environment.get(shlibpath_var, ""))
+    (config.shlibdir, config.llvm_libs_dir, config.environment.get(shlibpath_var, ""))
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kikairoya wrote:

> This is odd, how did this code work before? Was it moved here and no one noticed that the values are no longer expanded?

For Windows, since the pre-merge CI runs checks *without* `-DLLVM_LINK_LLVM_DYLIB=ON`, an additional `$PATH` isn't needed. llvm-mingw appears to do the same, although its releases are configured with dylib.

For Linux, DSOs are found via `RUNPATH` so `$LD_LIBRARY_PATH` isn't needed.

https://github.com/llvm/llvm-project/pull/163947