* dcrt0.cc (dll_crt0_0): Remove call to wincap.init.

	* dcrt0.cc (dll_crt0_0): Remove call to wincap.init.
	* init.cc (dll_entry): Rename is_wow64_proc to wow64_test_stack_marker.
	Call wincap.init here before doing anything else.  Use wincap.is_wow64
	to determine if we're running in a WOW64 emulator.
	* mmap.cc (MapViewNT): Don't use AT_ROUND_TO_PAGE in WOW64, it's
	apparently not supported.
	(mmap64): Don't create mappings beyond EOF, which would need to use
	AT_ROUND_TO_PAGE, on WOW64.
	* wincap.cc (wincap): Throw into the .cygwin_dll_common section.
	(wincapc::init): Determine if running in WOW64 and set wow_64 flag.
	* wincap.h (class wincapc): Add wow64 member.
	(wincapc::is_wow64): New method.