checknewapi.pl can run regview fine on Windows even if the name
doesn't include the .exe suffix. So drop the use of EXECPOST and then
this will work also in the case of cross-compilation to Windows, where
EXECPOST is .exe for HOST, but we aren't running a HOST regview but a
BUILD one.

Handle this using BUILD_TYPE instead.

This reverts commit 47b5eed7121305d375cfc9a6fd1ba21ff1430130.

Why this source file bothers including <malloc.h> at all (on platforms
where it exists) I have no idea... This is C++ for chrissake. And the
standard C location for the malloc() declaration is <stdlib.h> anyway.

Not needed now with a normal SAL_DLLEXTENSION defined for iOS.

This reverts commit dc915ed7fbbbeef9eefbf5bda07289a9462b6904.

Do it even if it can never be used successfully in an iOS app anyway,
as they are not supposed to load dynamic libraries (except system
ones).

this time run git add before commiting to commit the locally tested
version, and not some intermediate crap that was added in between