package/harfbuzz: needs gcc >= 4.8

Due to the version bump to 2.5.2 we need gcc >= 4.8.

Fixes:
http://autobuild.buildroot.net/results/924/9247b9773099d7995ad8fa1665dd768bb550f63c/

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/harfbuzz/Config.in

@@ -2,6 +2,7 @@ config BR2_PACKAGE_HARFBUZZ
 	bool "harfbuzz"
 	depends on BR2_INSTALL_LIBSTDCPP
 	depends on BR2_TOOLCHAIN_HAS_SYNC_4
+	depends on BR2_TOOLCHAIN_GCC_AT_LEAST_4_8
 	help
 	  HarfBuzz is an OpenType text shaping engine
 
@@ -10,6 +11,7 @@ config BR2_PACKAGE_HARFBUZZ
 	  Harfbuzz can make optional use of cairo, freetype,
 	  glib2 and icu packages if they are selected.
 
-comment "harfbuzz needs a toolchain w/ C++"
+comment "harfbuzz needs a toolchain w/ C++, gcc => 4.8"
 	depends on BR2_TOOLCHAIN_HAS_SYNC_4
-	depends on !BR2_INSTALL_LIBSTDCPP
+	depends on !BR2_INSTALL_LIBSTDCPP || \
+		!BR2_TOOLCHAIN_GCC_AT_LEAST_4_8