Some types on OpenVMS x86_64 (for example, `long') have different sizes
depending on whether compiled with either C or C++. In particular,
X-Windows applications crash if linked with the C++ version.
This patch makes `vms_make.com` create a second version of the FreeType
library compiled with C++ if OpenVMS is running on the x86_64 platform.
* src/sfnt/ttcolr.c (FT_PaintFormat_Internal): New enumeration values
`FT_COLR_PAINTFORMAT_INTERNAL_VAR_SKEW`,
`FT_COLR_PAINTFORMAT_INTERNAL_SKEW_CENTER`, and
`FT_COLR_PAINTFORMAT_INTERNAL_VAR_SKEW_CENTER`.
(read_paint): Handle new enumeration values.