[NFC] Correct outdated links to the Itanium C++ ABI documentation

Those are now hosted on GitHub.

rdar://problem/36557462

git-svn-id: https://llvm.org/svn/llvm-project/libunwind/trunk@358191 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/unwind.h b/include/unwind.h
index 122b57b..b6cc704 100644
--- a/include/unwind.h
+++ b/include/unwind.h
@@ -6,7 +6,7 @@
 //
 //
 // C++ ABI Level 1 ABI documented at:
-//   http://mentorembedded.github.io/cxx-abi/abi-eh.html
+//   https://itanium-cxx-abi.github.io/cxx-abi/abi-eh.html
 //
 //===----------------------------------------------------------------------===//
 
diff --git a/src/UnwindLevel1.c b/src/UnwindLevel1.c
index b3e30c4..bcb1a7f 100644
--- a/src/UnwindLevel1.c
+++ b/src/UnwindLevel1.c
@@ -6,7 +6,7 @@
 //
 //
 // Implements C++ ABI Exception Handling Level 1 as documented at:
-//      http://mentorembedded.github.io/cxx-abi/abi-eh.html
+//      https://itanium-cxx-abi.github.io/cxx-abi/abi-eh.html
 // using libunwind
 //
 //===----------------------------------------------------------------------===//