[llvm] [libc] add multi-platform pre-commit github actions (PR #119104)

[Schrodinger ZHU Yifan via llvm-commits]

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@@ -0,0 +1,76 @@
+# This workflow is for pre-commit testing of the LLVM-libc project.
+name: LLVM-libc Pre-commit Fullbuild Tests
+
+on:
+  pull_request:
+    branches: [ "main" ]
+    paths:
+      - 'libc/**'
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SchrodingerZhu wrote:

Should I also put in `compiler-rt`

https://github.com/llvm/llvm-project/pull/119104