disable -Werror=non-template-friend in llvm/ADT/PagedVector.h:215:59

Reported as the upstream issue:
llvm/llvm-project#67942

CMakeLists.txt

@@ -152,12 +152,17 @@ check_cxx_compiler_flag(
   SUPPORTS_MAYBE_UNINITIALIZED
 )
 
-# XXX remove in the future once LLVM 17 gets released 
 check_cxx_compiler_flag(
   "-Wclass-memaccess"
   SUPPORTS_CLASS_MEMACCESS
 )
 
+check_cxx_compiler_flag(
+  "-Wnon-template-friend"
+  SUPPORTS_NON_TEMPLATE_FRIEND
+)
+
+
 if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU"
     OR CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
   # XXX figure out how to get "-std=c++17 -fno-rtti" from LLVM.  That's how we
@@ -179,6 +184,10 @@ if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU"
     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-error=class-memaccess")
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-error=class-memaccess")
   endif()
+  if(SUPPORTS_NON_TEMPLATE_FRIEND)
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-error=non-template-friend")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-error=non-template-friend")
+  endif()
 
   set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -O3")
   set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELEASE} -O3 -g")