There is still at least one Microsoft-supported version of the CRT which
does not include the secure versions of various functions, and
consequently does not include `_set_invalid_parameter_handler`.
Tests for the definition and inclusion of
caml_install_invalid_parameter_handler refined to detect
`__STDC_SECURE_LIB__` defined in `crtdefs.h`. This is a badly documented,
but standardised, define. Although `__STDC_SECURE_LIB__` is compatible
with MinGW, I have retained the test for `_MSC_VER` and so kept this as an
MSVC-only patch.
ef2cdbe1e7