Integrate LLVM at llvm/llvm-project@791fe26d7581

Updates LLVM usage to match
[791fe26d7581](llvm/llvm-project@791fe26d7581)

PiperOrigin-RevId: 484191014

Author: tensorflower-gardener

third_party/llvm/workspace.bzl

@@ -4,8 +4,8 @@ load("//third_party:repo.bzl", "tf_http_archive")
 
 def repo(name):
     """Imports LLVM."""
-    LLVM_COMMIT = "fdac4c4e92e5a83ac5e4fa6d1d2970c0c4df8fa8"
-    LLVM_SHA256 = "df274c0e7c218f833e69b6ae5abce3000540f84f557fa3f4e57608ddae336351"
+    LLVM_COMMIT = "791fe26d758173e569d26d831b36ee8527e1a766"
+    LLVM_SHA256 = "409e689a40ddfd0654373477dc1a94730a38c62b2a8603f7ad02c805d4a2c1e7"
 
     tf_http_archive(
         name = name,