Disable -Wdeprecated-declarations in cmake builds

Summary:
[Folly] Disable `-Wdeprecated-declarations` in cmake builds.

To hide deprecation spam in unit-tests for uses of deprecated declarations which cannot yet be removed.

Reviewed By: Orvid

Differential Revision: D10287167

fbshipit-source-id: 2dddd9f69ca1dcced61e4a2d6cd16bad54b2a2ad

CMake/FollyCompilerUnix.cmake

@@ -19,8 +19,7 @@ function(apply_folly_compile_options_to_target THETARGET)
       -Werror
       -Wall
       -Wno-deprecated
-      -Wdeprecated-declarations
-      -Wno-error=deprecated-declarations
+      -Wno-deprecated-declarations
       -Wno-sign-compare
       -Wno-unused
       -Wunused-label