Revert the archive part of "Support/PathV2: Add identify_magic."

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123593 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Archive/Archive.cpp b/lib/Archive/Archive.cpp
index 1eab27d..3ee3cb2 100644
--- a/lib/Archive/Archive.cpp
+++ b/lib/Archive/Archive.cpp
@@ -116,10 +116,11 @@
 
   // Get the signature and status info
   const char* signature = (const char*) data;
-  SmallString<4> magic;
+  std::string magic;
   if (!signature) {
-    sys::fs::get_magic(path.str(), magic.capacity(), magic);
+    path.getMagicNumber(magic,4);
     signature = magic.c_str();
+    std::string err;
     const sys::FileStatus *FSinfo = path.getFileStatus(false, ErrMsg);
     if (FSinfo)
       info = *FSinfo;