692177d022
Although CMake adds warning flags, they are ignored in the libc++ headers because the headers '#pragma system header' themselves. This patch disables the system header pragma when building libc++ and fixes the warnings that arose. The warnings fixed were: 1. <memory> - anonymous structs are a GNU extension 2. <functional> - anonymous structs are a GNU extension. 3. <__hash_table> - Embedded preprocessor directives have undefined behavior. 4. <string> - Definition is missing noexcept from declaration. 5. <__std_stream> - Unused variable. git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@242623 91177308-0d34-0410-b5e6-96231b3b80d8