Disable test batch-mode-llvmIRHash-consistency

It fails in some configurations.

rdar://62338337

Author: aschwaighofer

test/multifile/batch-mode-llvmIRHash-consistency.swift

@@ -1,6 +1,9 @@
 // Ensure that the LLVMIR hash of the 2nd compilation in batch mode
 // is consistent no matter if the first one generates code or not.
 
+// This test fails in some configurations.
+// REQUIRES: rdar_62338337
+
 // RUN: %empty-directory(%t)
 // RUN: echo 'public enum E: Error {}' >%t/main.swift
 // RUN: echo >%t/other.swift