[LV] Reduce memory-check-threshold for test to preserve original test.

Future patches will remove some redundant instructions for runtime
checks, which brings this test case slightly below the default limit of
128. Force a lower limit to preserve the original spirit of the test
(checking that no interleaving happens if the number of checks is
above he threshold)

Author: fhahn

llvm/test/Transforms/LoopVectorize/PowerPC/interleaved-pointer-runtime-check-unprofitable.ll

@@ -1,5 +1,5 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt -mtriple=powerpc64-unknown-linux-gnu -mcpu=a2 -S -passes=loop-vectorize  < %s -o - | FileCheck %s
+; RUN: opt -mtriple=powerpc64-unknown-linux-gnu -mcpu=a2 -S -passes=loop-vectorize -vectorize-memory-check-threshold=60 < %s -o - | FileCheck %s
 
 ; The case will do aggressive interleave on PowerPC, resulting in a lot of memory checks.
 ; (On the A2, always unroll aggressively. In fact, if aggressive interleaving is enabled,