Fix gcc + binutils compilation. (#9024)

* fix binutils deptype for gcc

binutils needs to be a run dependency of gcc

* Fix gcc+binutils build on RHEL7+

static-libstdc++ is not available with system gcc.
Anyway, as it is for bootstraping, we do not really care depending on
a shared libstdc++.

Co-authored-by: Michael Kuhn <michael@ikkoku.de>

var/spack/repos/builtin/packages/gcc/package.py

@@ -115,7 +115,7 @@ class Gcc(AutotoolsPackage, GNUMirrorPackage):
     depends_on('zstd', when='@10:')
     depends_on('iconv', when='platform=darwin')
     depends_on('gnat', when='languages=ada')
-    depends_on('binutils~libiberty', when='+binutils')
+    depends_on('binutils~libiberty', when='+binutils', type=('build', 'link', 'run'))
     depends_on('zip', type='build', when='languages=java')
     depends_on('cuda', when='+nvptx')
 
@@ -373,8 +373,6 @@ def configure_args(self):
         # enable appropriate bootstrapping flags
         stage1_ldflags = str(self.rpath_args)
         boot_ldflags = stage1_ldflags + ' -static-libstdc++ -static-libgcc'
-        if '%gcc' in spec:
-            stage1_ldflags = boot_ldflags
         options.append('--with-stage1-ldflags=' + stage1_ldflags)
         options.append('--with-boot-ldflags=' + boot_ldflags)