toolchain-external: mark Synopsys toolchain as broken

This uClibc toolchain does not provide an appropriate uClibc
configuration for Buildroot: missing IPv6, missing nsl stub, missing
program invocation, etc. Therefore, we mark it as broken, waiting for
a new upstream release of a new toolchain.

We keep around the toolchain-external Synopsys code anyway, since it
will most likely be identical for the new toolchain version. However,
we remove all the quirks that were introduced to start work around
issues related to this toolchain.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
diff --git a/toolchain/toolchain-external/Config.in b/toolchain/toolchain-external/Config.in
index 9433101..665a15b 100644
--- a/toolchain/toolchain-external/Config.in
+++ b/toolchain/toolchain-external/Config.in
@@ -837,6 +837,10 @@
 	bool "Synopsys ARC 2014.12 toolchain"
 	depends on BR2_arc
 	depends on BR2_HOSTARCH = "x86_64"
+	# does not provide IPv6, and lacks many uClibc features
+	# expected by Buildroot. The next Synopsys toolchain version
+	# should fix those problems.
+	depends on BROKEN
 	select BR2_TOOLCHAIN_EXTERNAL_UCLIBC
 	select BR2_INSTALL_LIBSTDCPP
 	select BR2_TOOLCHAIN_HAS_NATIVE_RPC