The behaviour changed in GNU make 4.3, where `#` (without the backslash)
would be necessary. Using a variable instead the code works with both older
and newer GNU make versions.
Fixes#1252.
* 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.
Alexei Podtelezhnikov
Werner Lemberg
Xiang Xiao
Dominik Röttsches