+JH/22 Taint checking: move to a hybrid approach for checking. Previously, one
+ of two ways was used, depending on a build-time flag. The fast method
+ relied on assumptions about the OS and libc malloc, which were known to
+ not hold for the BSD-derived platforms, and discovered to not hold for
+ 32-bit Linux either. In fact the glibc documentation describes cases
+ where these assumptions do not hold. The new implementation tests for
+ the situation arising and actively switches over from fast to safe mode.
+