[compiler-rt] Make the MSAN wmemset intercepter call wmemset instead of memset. Fixes PR 21579

Summary:
Exactly what the title says. I've tested this change against the libc++ test failures and it solves all of them. The check-msan rule also still passes.
I'm not sure why it called memset originally. 

I can add tests if requested but currently there are no tests involving wide chars and they are a c++11 features.

Reviewers: kcc, eugenis

Reviewed By: eugenis

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D6352

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@222673 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 10 insertions, 0 deletions

diff --git a/lib/msan/tests/msan_test.cc b/lib/msan/tests/msan_test.cc
index 12012a05a..84fa9623e 100644
--- a/lib/msan/tests/msan_test.cc
+++ b/lib/msan/tests/msan_test.cc
@@ -1834,6 +1834,16 @@ TEST(MemorySanitizer, wcsnrtombs) {
   EXPECT_POISONED(buff[2]);
 }
 
+TEST(MemorySanitizer, wmemset) {
+    wchar_t x[25];
+    break_optimization(x);
+    EXPECT_POISONED(x[0]);
+    wmemset(x, L'A', 10);
+    EXPECT_EQ(x[0], L'A');
+    EXPECT_EQ(x[9], L'A');
+    EXPECT_POISONED(x[10]);
+}
+
 TEST(MemorySanitizer, mbtowc) {
   const char *x = "abc";
   wchar_t wx;