bug#42185: An issue with bcrypt.h [MSYS2/MinGW64?]

[Angelo Graziosi]

This morning building the last master (32b3856f850e1) I get these warning while 
configuring:

[...]
checking whether getloadavg is declared... no
checking bcrypt.h usability... no
checking bcrypt.h presence... yes
configure: WARNING: bcrypt.h: present but cannot be compiled
configure: WARNING: bcrypt.h:     check for missing prerequisite headers?
configure: WARNING: bcrypt.h: see the Autoconf documentation
configure: WARNING: bcrypt.h:     section "Present But Cannot Be Compiled"
configure: WARNING: bcrypt.h: proceeding with the compiler's result
configure: WARNING:     ## ------------------------------------ ##
configure: WARNING:     ## Report this to bug-gnu-emacs@gnu.org ##
configure: WARNING:     ## ------------------------------------ ##
checking for bcrypt.h... no
checking whether the bcrypt library is guaranteed to be present... (cached) no
checking whether gettimeofday clobbers localtime buffer... no
checking for gettimeofday with POSIX signature... yes
[...]

The above occurred with the Windows build (MSYS2/MinGW64).