package/rwmem: needs wchar

rwmmem needs wchar because of fmt dependency since its addition in
commit 51a282bcb8dfc26d3a27723383c5a1767653a19d

Fixes:
 - http://autobuild.buildroot.org/results/1c06c27d70aae8bdb39ae43fbe74896e536293c6

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/rwmem/Config.in

@@ -2,9 +2,14 @@ config BR2_PACKAGE_RWMEM
 	bool "rwmem"
 	depends on BR2_TOOLCHAIN_GCC_AT_LEAST_5
 	depends on BR2_INSTALL_LIBSTDCPP
+	depends on BR2_USE_WCHAR # fmt
 	select BR2_PACKAGE_FMT
 	select BR2_PACKAGE_INIH
 	help
 	  Simple program to read/write from/to any location in memory.
 
 	  https://github.com/tomba/rwmem
+
+comment "rwmem needs a toolchain w/ C++, wchar, gcc >= 5"
+	depends on !BR2_INSTALL_LIBSTDCPP || !BR2_USE_WCHAR || \
+		!BR2_TOOLCHAIN_GCC_AT_LEAST_5