Disable warning C4291 on MSVC. Caused because class AttributeList provides a non implemented operator delete without a corresponding new. 

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119902 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 62a08b2..2c2c115 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -232,7 +232,7 @@
   add_llvm_definitions( -D_SCL_SECURE_NO_WARNINGS -DCRT_NONSTDC_NO_WARNINGS )
   add_llvm_definitions( -D_SCL_SECURE_NO_DEPRECATE )
   add_llvm_definitions( -wd4146 -wd4503 -wd4996 -wd4800 -wd4244 -wd4624 )
-  add_llvm_definitions( -wd4355 -wd4715 -wd4180 -wd4345 -wd4224 -wd4267 )
+  add_llvm_definitions( -wd4355 -wd4715 -wd4180 -wd4345 -wd4224 -wd4267 -wd4291 )
 
   # Suppress 'new behavior: elements of array 'array' will be default initialized'
   add_llvm_definitions( -wd4351 )