lib: Adapt c18n build options to updated libunwind

The option has been renamed and should also work just fine for
libgcc_eh.a, not just libgcc_s.so.1. It's not very useful as it will
just use the stubs, but it keeps the configuration consistent between
static and dynamic libraries, and matches what libunwind's build system
will do. In theory with sub-library (really sub-object) compartments one
could also embed enough of the c18n runtime in libc.a to support
compartmentalising static binaries so it's not a completely stupid
configuration to have and we might as well leave the infrastructure in
to support it whenever it's easy to do so.

lib/libgcc_eh/Makefile.inc

@@ -22,6 +22,9 @@ SRCS+=		${SRCS_EXC}
 CFLAGS.UnwindLevel1-gcc-ext.c+=	-D_LIBUNWIND_SUPPORT_FRAME_APIS
 .endif
 .endif
+.if ${MACHINE_ABI:Mpurecap} && ${MACHINE_CPUARCH} == "aarch64"
+CFLAGS+=	-D_LIBUNWIND_HAS_CHERI_LIB_C18N
+.endif
 .for file in ${SRCS_EXC:M*.c}
 CFLAGS.${file}+=	-fno-exceptions -funwind-tables
 .if ${MK_ASAN} != "no"

lib/libgcc_s/Makefile

@@ -52,9 +52,4 @@ SRCS+=		s_logbl.c
 SRCS+=		s_scalbnl.c
 .endif
 
-.if ${MACHINE_ABI:Mpurecap} && ${MACHINE_CPUARCH} == "aarch64"
-SYMBOL_MAPS+=	${.CURDIR}/Symbol-c18n.map
-CFLAGS+=	-D_LIBUNWIND_CHERI_C18N_SUPPORT
-.endif
-
 .include <bsd.lib.mk>