Add ARC support

This adds support for the ARC architecture to libffi. DesignWare ARC
is a family of processors from Synopsys, Inc.

This patch has been tested on a little-endian system and passes
the testsuite.

Signed-off-by: Mischa Jonker <mjonker@synopsys.com>

configure.ac

@@ -77,6 +77,10 @@ case "$host" in
 	HAVE_LONG_DOUBLE='defined(__LONG_DOUBLE_128__)'
 	;;
 
+  arc*-*-*)
+	TARGET=ARC; TARGETDIR=arc
+	;;
+
   arm*-*-*)
 	TARGET=ARM; TARGETDIR=arm
 	;;
@@ -289,6 +293,7 @@ AM_CONDITIONAL(POWERPC_AIX, test x$TARGET = xPOWERPC_AIX)
 AM_CONDITIONAL(POWERPC_DARWIN, test x$TARGET = xPOWERPC_DARWIN)
 AM_CONDITIONAL(POWERPC_FREEBSD, test x$TARGET = xPOWERPC_FREEBSD)
 AM_CONDITIONAL(AARCH64, test x$TARGET = xAARCH64)
+AM_CONDITIONAL(ARC, test x$TARGET = xARC)
 AM_CONDITIONAL(ARM, test x$TARGET = xARM)
 AM_CONDITIONAL(AVR32, test x$TARGET = xAVR32)
 AM_CONDITIONAL(LIBFFI_CRIS, test x$TARGET = xLIBFFI_CRIS)