gdb: move libiberty.m4 to gdbsupport

This is used by gdb, gdbsupport, and gdbserver.  We want to use it
in the sim tree too.  Move it to gdbsupport which is meant as the
common sharing space for these projects.

Approved-By: Tom Tromey <tom@tromey.com>

gdb/acinclude.m4

@@ -48,7 +48,7 @@ m4_include([../config/zstd.m4])
 m4_include([../gdbsupport/common.m4])
 
 dnl For libiberty_INIT.
-m4_include(libiberty.m4)
+m4_include(../gdbsupport/libiberty.m4)
 
 dnl For GDB_AC_PTRACE.
 m4_include(../gdbsupport/ptrace.m4)

gdbserver/acinclude.m4

@@ -19,7 +19,7 @@ m4_include(../config/codeset.m4)
 m4_include(../gdbsupport/common.m4)
 
 dnl For libiberty_INIT.
-m4_include(../gdb/libiberty.m4)
+m4_include(../gdbsupport/libiberty.m4)
 
 dnl For GDB_AC_PTRACE.
 m4_include(../gdbsupport/ptrace.m4)

gdbsupport/Makefile.in

@@ -128,9 +128,10 @@ am__aclocal_m4_deps = $(top_srcdir)/../config/codeset.m4 \
 	$(top_srcdir)/../bfd/bfd.m4 $(top_srcdir)/common.m4 \
 	$(top_srcdir)/../config/ax_pthread.m4 \
 	$(top_srcdir)/../gdb/ax_cxx_compile_stdcxx.m4 \
-	$(top_srcdir)/../gdb/libiberty.m4 $(top_srcdir)/selftest.m4 \
-	$(top_srcdir)/ptrace.m4 $(top_srcdir)/compiler-type.m4 \
-	$(top_srcdir)/warning.m4 $(top_srcdir)/configure.ac
+	$(top_srcdir)/../gdbsupport/libiberty.m4 \
+	$(top_srcdir)/selftest.m4 $(top_srcdir)/ptrace.m4 \
+	$(top_srcdir)/compiler-type.m4 $(top_srcdir)/warning.m4 \
+	$(top_srcdir)/configure.ac
 am__configure_deps = $(am__aclocal_m4_deps) $(CONFIGURE_DEPENDENCIES) \
 	$(ACLOCAL_M4)
 DIST_COMMON = $(srcdir)/Makefile.am $(top_srcdir)/configure \

gdbsupport/acinclude.m4

@@ -2,7 +2,7 @@ m4_include([../bfd/bfd.m4])
 m4_include([common.m4])
 m4_include([../config/ax_pthread.m4])
 m4_include([../gdb/ax_cxx_compile_stdcxx.m4])
-m4_include([../gdb/libiberty.m4])
+m4_include([../gdbsupport/libiberty.m4])
 m4_include([selftest.m4])
 m4_include([ptrace.m4])