app-editors/emacs: Fix build failure with 17.0 profiles.

The following comment from upstream is in configure.ac of emacs-25.3:
"-no-pie or -nopie fixes a temacs segfault on Gentoo, OpenBSD, Ubuntu,
and other systems with "hardened" GCC configurations for some reason
(Bug#18784).  We don't know why this works, but not segfaulting is
better than segfaulting."

Adding -no-pie to 23.4 and 24.5 appears to make them build, too.
Note that only append-ldflags fixes the build failure, while
append-flags does not (at least not for 23.4).

Thanks to Mats Lidell for pointing me to the above upstream comment.

Closes: https://bugs.gentoo.org/639568
Closes: https://bugs.gentoo.org/639570
Package-Manager: Portage-2.3.17, Repoman-2.3.6

app-editors/emacs/emacs-23.4-r16.ebuild

@@ -104,6 +104,7 @@ src_configure() {
 	strip-flags
 	filter-flags -fstrict-aliasing -pie
 	append-flags $(test-flags -fno-strict-aliasing)
+	append-ldflags $(test-flags -no-pie)	#639568
 
 	if use sh; then
 		replace-flags "-O[1-9]" -O0		#262359

app-editors/emacs/emacs-24.5-r4.ebuild

@@ -97,6 +97,7 @@ src_prepare() {
 src_configure() {
 	strip-flags
 	filter-flags -pie					#526948
+	append-ldflags $(test-flags -no-pie)	#639570
 
 	if use sh; then
 		replace-flags "-O[1-9]" -O0		#262359