[llvm] Add macOS premerge check workflow (PR #207435)

[Mishal Shah via llvm-commits]

================
@@ -132,19 +132,26 @@
 
 EXCLUDE_MAC = {
     "bolt",
-    "compiler-rt",
+    "CIR",  # Depends on mlir, which is excluded below.
     "cross-project-tests",
     "flang",
+    "flang-rt",
     "libc",
-    "lldb",
+    "mlir",
     "openmp",
     "polly",
     "libcxx",
     "libcxxabi",
-    "libunwind",
----------------
shahmishal wrote:

Resolved by https://github.com/llvm/llvm-project/pull/207435/commits/6e1e4fe6bb97f26a85cf2f433d5763f2cdd2017d

https://github.com/llvm/llvm-project/pull/207435