Use memcmp.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134439 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Object/COFFObjectFile.cpp b/lib/Object/COFFObjectFile.cpp
index e4b13b2..1453efb 100644
--- a/lib/Object/COFFObjectFile.cpp
+++ b/lib/Object/COFFObjectFile.cpp
@@ -309,9 +309,7 @@
     if (!checkSize(Data, ec, 0x3c + 8)) return;
     HeaderStart += *reinterpret_cast<const ulittle32_t *>(base() + 0x3c);
     // Check the PE header. ("PE\0\0")
-    StringRef Actual(reinterpret_cast<const char *>(base() + HeaderStart), 4);
-    StringRef Expected("PE\0\0", 4);
-    if (Actual != Expected) {
+    if (std::memcmp(base() + HeaderStart, "PE\0\0", 4) != 0) {
       ec = object_error::parse_failed;
       return;
     }