Revert "Add tests for the bit_struct! macro."

This reverts commit dd44a7d24affbef1841bf8aa4c8c0e9c3c4989f0.
Revert "fixup! Move PropertyBitField to a syntax extension."

This reverts commit 653f257029466fcc587d6ba17495a663cbd1693b.
Revert "Move PropertyBitField to a syntax extension."

This reverts commit d6002a0a50f4c9fab7bcaf592b296123d33ac212.
Merge pull request #3194 from glennw/android-build

Revert syntax extension for now, as it causes issues with cross compiling for android.