invoke.texi (fwritable-relocated-rdata): Document new Cygwin/MinGW target option.
* doc/invoke.texi (fwritable-relocated-rdata): Document
new Cygwin/MinGW target option.
* config/i386/winnt.c (i386_pe_unique_section): Ignore
reloc if flag -fwritable-relocated-rdata is not set.
(i386_pe_section_type_flags): Likewise.
* config/i386/cygming.opt (fwritable-relocated-rdata):
Add new flag variable flag_writable_rel_rdata.