update xfail target parsing

Author: mustartt

flang/test/HLFIR/unroll-loops.fir

@@ -4,7 +4,7 @@
 // RUN: %flang_fc1 -emit-llvm -O1 -mllvm -force-vector-width=2 -o- %s | FileCheck %s --check-prefixes=CHECK,NO-UNROLL
 
 // FIXME: https://github.com/llvm/llvm-project/issues/123668
-// XFAIL: powerpc64{{(le)?}}-target-arch
+// XFAIL: target=powerpc64{{.*}}
 
 // CHECK-LABEL: @unroll
 // CHECK-SAME: (ptr nocapture writeonly %[[ARG0:.*]])

flang/test/Integration/unroll-loops.f90

@@ -4,7 +4,7 @@
 ! RUN: %flang_fc1 -emit-llvm -O1 -mllvm -force-vector-width=2 -o- %s | FileCheck %s --check-prefixes=CHECK,NO-UNROLL
 
 ! FIXME: https://github.com/llvm/llvm-project/issues/123668
-! XFAIL: powerpc64{{(le)?}}-target-arch
+! XFAIL: target=powerpc64{{.*}}
 
 ! CHECK-LABEL: @unroll
 ! CHECK-SAME: (ptr nocapture writeonly %[[ARG0:.*]])