[LV] Reland testcase in 0ec4cae

(cherry picked from commit ac67ec3)

Author: sushgokh

llvm/test/Transforms/LoopVectorize/AArch64/reg-usage.ll

@@ -17,8 +17,8 @@ define void @get_invariant_reg_usage(ptr %z) {
 ; CHECK-NEXT: LV(REG): Found max usage: 1 item
 ; CHECK-NEXT: LV(REG): RegisterClass: Generic::ScalarRC, 3 registers
 ; CHECK-NEXT: LV(REG): Found invariant usage: 2 item
-; CHECK-NEXT: RegisterClass: Generic::ScalarRC, 2 registers
-; CHECK-NEXT: RegisterClass: Generic::VectorRC, 8 registers 
+; CHECK-NEXT: LV(REG): RegisterClass: Generic::ScalarRC, 2 registers
+; CHECK-NEXT: LV(REG): RegisterClass: Generic::VectorRC, 8 registers 
 
 L.entry:
   %0 = load i128, ptr %z, align 16