Fix a typo: overidden -> overridden - Patch from Kai Zhao

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@245539 91177308-0d34-0410-b5e6-96231b3b80d8

src/new.cpp

@@ -38,7 +38,7 @@
 #ifndef __GLIBCXX__
 
 // Implement all new and delete operators as weak definitions
-// in this shared library, so that they can be overriden by programs
+// in this shared library, so that they can be overridden by programs
 // that define non-weak copies of the functions.
 
 _LIBCPP_WEAK _LIBCPP_NEW_DELETE_VIS