package/elfutils: elfutils programs now require a c++ toolchain

The 0.192 release of elfutils introduced the src/srcfiles.cxx program,
that lists all source files of a given ELF binary. As this is a C++
program, we need a toolchain that supports it.

Without it, the build system tries to use "no" as the CXX compiler,
resulting in the following errors :

  /bin/sh: line 1: no: command not found

as can be seen here for example :

https://autobuild.buildroot.net/results/849/849221c794a469a423857a290db775d150b84900

Add a dependency to a CPP toolchain for the elfutils programs.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: Julien Olivain <ju.o@free.fr>

package/elfutils/Config.in

@@ -24,11 +24,13 @@ if BR2_PACKAGE_ELFUTILS
 config BR2_PACKAGE_ELFUTILS_PROGS
 	bool "Install programs"
 	depends on BR2_TOOLCHAIN_USES_GLIBC
+	depends on BR2_INSTALL_LIBSTDCPP
 	help
 	  This option tells elfutils to not only install the libelf
 	  libraries, but also the elfutils programs.
 
-comment "elfutils programs needs a glibc toolchain"
-	depends on !BR2_TOOLCHAIN_USES_GLIBC
+comment "elfutils programs needs a glibc toolchain w/ C++"
+	depends on !BR2_TOOLCHAIN_USES_GLIBC \
+		|| !BR2_INSTALL_LIBSTDCPP
 
 endif