[llvm] Migrate away from legacy external runfiles (PR #203650)

[Shantanu Gontia via llvm-commits]

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@@ -37,19 +37,26 @@ def lit_test(
         name = name,
         srcs = [Label("//llvm:lit")],
         main = Label("//llvm:utils/lit/lit.py"),
-        args = args + ["-v"] + ["$(execpath %s)" % src for src in srcs],
+        args = args + ["-v"] + ["$(rootpath %s)" % src for src in srcs],
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shantanu-gontia wrote:

https://bazel.build/reference/be/make-variables#predefined_label_variables

Denotes the path that a built binary can use to find a dependency at runtime relative to the subdirectory of its runfiles directory corresponding to the main repository.

https://github.com/llvm/llvm-project/pull/203650