toolchain/toolchain-external/toolchain-external-synopsys-arc: mark as broken

The ARC toolchains from Synopsys unfortunately are not "pure"
toolchains: their sysroot no only contains the C library, but also
additional libraries, most notably libncurses and libexpat.

This confuses Buildroot, and causes build issues, and is anyway not a
supported situation. Until the toolchains get fixed, let's mark them
as broken.

Fixes:

  http://autobuild.buildroot.net/results/38766332c391ce97a566c6e2255a947e6074152b/
  (and possibly a number of others)

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Julien Olivain <ju.o@free.fr>

toolchain/toolchain-external/toolchain-external-synopsys-arc/Config.in

@@ -5,6 +5,10 @@ config BR2_TOOLCHAIN_EXTERNAL_SYNOPSYS_ARC
 		BR2_archs4x_rel31 || BR2_archs4x
 	depends on BR2_HOSTARCH = "x86_64"
 	depends on !BR2_ARCH_NEEDS_GCC_AT_LEAST_15
+	# The toolchains have libncurses and libexpat in their
+	# sysroot, confusing Buildroot and causing build
+	# issues. Disable until the toolchains get fixed.
+	depends on BR2_BROKEN
 	select BR2_INSTALL_LIBSTDCPP
 	select BR2_TOOLCHAIN_HAS_SSP
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_5_16