* Makefile.in: Add some more optimization flags for cygwait, malloc and path. Explain

* Makefile.in: Add some more optimization flags for cygwait, malloc and path.  Explain
why -fomit-frame-pointer doesn't work right for passwd.o and path.o.  Add
-static to link command line for cygwin0.dll.
* fhandler_disk_file.cc (fhandler_disk_file::facl): Reorganize slightly to
silence compiler warning when compiling with -fstack-check.
* net.cc (inet_ntop6): Initialize structure members to silence compiler warning
when compiling with -fstack-check.
* pseudo-reloc.cc (_pei386_runtime_relocator): Make this a C function.  Detect
NULL u.
* winsup.h (_pei386_runtime_relocator): Declare this as extern "C".
* lib/_cygwin_crt0_common.cc (_pei386_runtime_relocator): Call with NULL
argument.
* signal.cc (sigaction_worker): Eliminate last argument.  Let callers report
their own strace info.  Regparmize.
(sigaction): Reflect sigaction_worker changes.
(siginterrupt): Ditto.
* exceptions.cc: Update copyright.