package/binutils: zlib is mandatory

As found out by Yann [1], binutils will use its bundled copy of zlib,
whether it is already provided by the system or not, and unless
explicitly told to use the system zlib with --with-system-zlib, which
is available since version 2.21 and
https://github.com/bminor/binutils-gdb/commit/700d40ca16eb3ba1ecc1e602cb3eec175bdf70f0

This will fix the following build failure with oprofile when compiling
in a static configuration where zlib is not enabled:

    checking for bfd_openr in -lbfd... no
    checking for compress in -lz... no
    configure: error: libz library not found; required by libbfd

As found out by Arnout [1], this fails infrequently because static is
already pretty rare, but in addition zlib is almost always selected by
some other package.

Fixes:
 - http://autobuild.buildroot.org/results/0e1d16dfbb455a08db80ac5d35613908c3b4163f

[1] https://patchwork.ozlabs.org/project/buildroot/patch/20211030214734.2154583-1-fontaine.fabrice@gmail.com/

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
[yann.morin.1998@free.fr:
  - reword the explanations about the system zlib
  - extend the oprofile example with static and !zlib
]
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

package/binutils/Config.in

@@ -2,6 +2,7 @@ config BR2_PACKAGE_BINUTILS
 	bool "binutils"
 	depends on !BR2_nios2
 	depends on BR2_USE_WCHAR
+	select BR2_PACKAGE_ZLIB
 	help
 	  Install binutils on the target
 

package/binutils/binutils.mk

@@ -25,7 +25,7 @@ BINUTILS_SITE ?= $(BR2_GNU_MIRROR)/binutils
 BINUTILS_SOURCE ?= binutils-$(BINUTILS_VERSION).tar.xz
 BINUTILS_EXTRA_CONFIG_OPTIONS = $(call qstrip,$(BR2_BINUTILS_EXTRA_CONFIG_OPTIONS))
 BINUTILS_INSTALL_STAGING = YES
-BINUTILS_DEPENDENCIES = $(TARGET_NLS_DEPENDENCIES)
+BINUTILS_DEPENDENCIES = zlib $(TARGET_NLS_DEPENDENCIES)
 BINUTILS_MAKE_OPTS = LIBS=$(TARGET_NLS_LIBS)
 BINUTILS_LICENSE = GPL-3.0+, libiberty LGPL-2.1+
 BINUTILS_LICENSE_FILES = COPYING3 COPYING.LIB
@@ -51,6 +51,7 @@ BINUTILS_CONF_OPTS = \
 	--target=$(GNU_TARGET_NAME) \
 	--enable-install-libiberty \
 	--enable-build-warnings=no \
+	--with-system-zlib \
 	$(BINUTILS_DISABLE_GDB_CONF_OPTS) \
 	$(BINUTILS_EXTRA_CONFIG_OPTIONS)
 
@@ -74,10 +75,6 @@ ifeq ($(BR2_ARM_CPU_ARMV7M)$(BR2_OPTIMIZE_S),yy)
 BINUTILS_CONF_ENV += CFLAGS="$(TARGET_CFLAGS) -O2"
 endif
 
-ifeq ($(BR2_PACKAGE_ZLIB),y)
-BINUTILS_DEPENDENCIES += zlib
-endif
-
 # "host" binutils should actually be "cross"
 # We just keep the convention of "host utility" for now
 HOST_BINUTILS_CONF_OPTS = \