Default bash on macOS (v. 3.x) doesn't support |& syntax

Author: AlexDenisov

mlir/test/mlir-cpu-runner/invalid.mlir

@@ -1,4 +1,4 @@
-// RUN: not mlir-cpu-runner --no-implicit-module %s |& FileCheck %s
+// RUN: not mlir-cpu-runner --no-implicit-module %s 2>&1 | FileCheck %s
 
 // CHECK: Error: top-level op must be a symbol table.
 llvm.func @main()

mlir/test/mlir-reduce/invalid.mlir

@@ -1,6 +1,6 @@
 // UNSUPPORTED: system-windows
-// RUN: not mlir-reduce -opt-reduction-pass --no-implicit-module %s |& FileCheck %s --check-prefix=CHECK-PASS
-// RUN: not mlir-reduce -reduction-tree --no-implicit-module %s |& FileCheck %s --check-prefix=CHECK-TREE
+// RUN: not mlir-reduce -opt-reduction-pass --no-implicit-module %s 2>&1 | FileCheck %s --check-prefix=CHECK-PASS
+// RUN: not mlir-reduce -reduction-tree --no-implicit-module %s 2>&1 | FileCheck %s --check-prefix=CHECK-TREE
 
 // The reduction passes are currently restricted to 'builtin.module'.
 // CHECK-PASS: error: Can't add pass '{{.+}}' restricted to 'builtin.module' on a PassManager intended to run on 'func.func'