toolchain: disable C++ support on AVR32 gcc 4.2 with uClibc

In 25c3160092d7 ("uClibc 0.9.31: remove stray kludges/conditions"), a
conditional that prevents the combination gcc 4.2-avr / C++ / locale
with uClibc 0.9.31 was removed. However, it turns out that the same
problem is affecting uClibc 0.9.33, described at
http://comments.gmane.org/gmane.comp.lib.uclibc.buildroot/24260.

Therefore, we prevent the combination of gcc 4.2-avr / C++ / locale to
happen.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

toolchain/toolchain-buildroot/Config.in.2

@@ -7,11 +7,16 @@ comment "Toolchain Options"
 config BR2_TOOLCHAIN_BUILDROOT_CXX
 	bool "Enable C++ support"
 	select BR2_INSTALL_LIBSTDCPP
+	depends on !(BR2_GCC_VERSION_4_2_2_AVR32_2_1_5 && \
+		     BR2_TOOLCHAIN_BUILDROOT_LOCALE)
 	help
 	  Enable this option if you want your toolchain to support the
 	  C++ language and you want C++ libraries to be installed on
 	  your target system.
 
+comment "C++ support broken in uClibc with locale enabled with gcc 4.2"
+	depends on BR2_GCC_VERSION_4_2_2_AVR32_2_1_5 && BR2_TOOLCHAIN_BUILDROOT_LOCALE
+
 config BR2_TOOLCHAIN_BUILDROOT_USE_SSP
 	bool "Enable stack protection support"
 	help