[llvm-mca] Add test case (NFC)

Add test case that will serve as the base for D54777.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@347434 91177308-0d34-0410-b5e6-96231b3b80d8

test/tools/llvm-mca/AArch64/Cyclone/register-offset.s

@@ -0,0 +1,9 @@
+# RUN: not llvm-mca -march=aarch64 -mcpu=cyclone -resource-pressure=false < %s |& FileCheck %s
+# UNSUPPORTED: -windows-
+
+  ldr	x7, [x1, #8]
+  ldr	x6, [x1, x2]
+  ldr	x4, [x1, x2, sxtx]
+
+# CHECK: error
+# CHECK-SAME: unable to resolve scheduling class for write variant.