Roll llvm-project from 72ba78c29e92 to c4ed142e695f (8 revisions)

https://chromium.googlesource.com/external/github.com/llvm/llvm-project.git/+log/72ba78c29e92..c4ed142e695f

2021-05-06 cyndy_ishida@apple.com [llvm][TextAPI] add mapping from OS string to Platform
2021-05-06 Stanislav.Mekhanoshin@amd.com [AMDGPU] Expose __builtin_amdgcn_perm for v_perm_b32
2021-05-06 rob.suderman@gmail.com [mlir][tosa] Added div op, variadic concat. Removed placeholder. Spec v0.22 alignment.
2021-05-06 jonathanchesterfield@gmail.com [libomptarget][nfc] Refactor amdgpu partial barrier to simplify adding a second one
2021-05-06 amy.zhuang@intel.com [mlir] Update dstNode after DenseMap insertion in loop fusion pass.
2021-05-06 malhar.jajoo@arm.com [ARM] Transforming memcpy to Tail predicated Loop
2021-05-06 jonathanchesterfield@gmail.com [libomptarget][amdgpu][nfc] Remove dead code from amdgpu plugin
2021-05-06 antiagainst@google.com [mlir][spirv] NFC: Replace OwningSPIRVModuleRef with OwningOpRef

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Change-Id: I0cad0585f8c16cbc82466dbd5c3f4b5bd1b68705
Reviewed-on: https://chromium-review.googlesource.com/c/emscripten-releases/+/2878927
Commit-Queue: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Bot-Commit: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
diff --git a/DEPS b/DEPS
index a07629c..cefff03 100644
--- a/DEPS
+++ b/DEPS
@@ -24,7 +24,7 @@
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling llvm_project
   # and whatever else without interference from each other.
-  'llvm_project_revision': '72ba78c29e923cb6e5d89eb5ea8180bf723188be',
+  'llvm_project_revision': 'c4ed142e695f14ba5675ec6d12226ee706329a0f',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling v8
   # and whatever else without interference from each other.