[Fontconfig] relocations, readonly data

[Matthias Clasen]

Since one of the main goals of the mmap cache effort is memory
reduction, would it make sense to apply (the parts that still
apply) the patch in 2638 to move some constant data like the 
glyph<n> variables in fcglyphname.h from .data to .rodata ?

Another interesting bug in this area is 2878, which complains that
all the FcCharSets in fcLangCharSets are stored in .data and cause
relocations, although they are not modified at runtime. It seems to me
that it should be possible to fix this by generating the charsets
in the form in which fc-cache stores them in the mmap cache, but I have
not been able to work out the details.


Matthias