Do not use defined inside macros
Do not use defined inside macros

This causes warnings on newer GCC and Clang versions that enable
-Wexpansion-to-defined by default.

mongodb/libbson,mongodb/libbson,ajdavis/libbson,rcsanchez97/libbson,mapr/libbson,mapr/libbson,mongodb/libbson,ajdavis/libbson,rcsanchez97/libbson,rcsanchez97/libbson,mapr/libbson,ajdavis/libbson