Revert "[SLC] Preserve attrs for strncpy(x, "", y) -> memset(align 1 x, '\0', y)"

Summary:
This reverts commit r372101.

Causes ASAN build bot failures:

http://lab.llvm.org:8011/builders/sanitizer-ppc64be-linux/builds/14176
From http://lab.llvm.org:8011/builders/sanitizer-ppc64be-linux/builds/14176/steps/64-bit%20check-asan/logs/stdio:

```
[ RUN      ] AddressSanitizer.StrNCatOOBTest
/home/buildbots/ppc64be-sanitizer/sanitizer-ppc64be/build/llvm-project/compiler-rt/lib/asan/tests/asan_str_test.cpp:462: Failure
Death test: strncat(to - 1, from, 0)
    Result: failed to die.
```

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67658

llvm-svn: 372125

1 files changed, 1 insertions, 4 deletions

diff --git a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
index a5e31f21166..217f929e9ad 100644
--- a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -610,10 +610,7 @@ Value *LibCallSimplifier::optimizeStrNCpy(CallInst *CI, IRBuilder<> &B) {
 
   if (SrcLen == 0) {
     // strncpy(x, "", y) -> memset(align 1 x, '\0', y)
-    CallInst *NewCI = B.CreateMemSet(Dst, B.getInt8('\0'), Size, 1);
-    AttrBuilder ArgAttrs(CI->getAttributes().getParamAttributes(0));
-    NewCI->setAttributes(NewCI->getAttributes().addParamAttributes(
-        CI->getContext(), 0, ArgAttrs));
+    B.CreateMemSet(Dst, B.getInt8('\0'), Size, 1);
     return Dst;
   }