Add fold_latin1 to the list of exported variable symbols in libperl.a

Hello,

the build of re.pm was breaking for me on Win32+gcc due to a missing 
symbol. Nicholas pointed out that likely, fold_latin1 was not properly 
exported. The attached patch adds fold_latin1 to global.sym and that 
makes it exported and the build and test works On My Machine.

Hence please apply this patch.

Thanks,
-max

• Add fold_latin1 to the list of exported variable symbols in libperl.a by Max Maischein
• Re: Add fold_latin1 to the list of exported variable symbols in libperl.a by Nicholas Clark