Add %{_bindir} to PATH to cater CdnX-builds.

Set CFLAGS_FOR_BUILD.

contrib/crossrpms/binutils/build.add

@@ -1,10 +1,16 @@
 %build
+%if "%{_prefix}" != "/usr"
+  export PATH="%{_bindir}:${PATH}"
+%endif
 %if "@tool_target@" == "i686-pc-cygwin"
 # The cygwin sources are leaking memory
   RPM_OPT_FLAGS="$(echo "$RPM_OPT_FLAGS"|sed -e 's; -Wp,-D_FORTIFY_SOURCE=2;;')"
 %endif
   mkdir -p build
   cd build
+%if "%{_build}" != "%{_host}"
+  CFLAGS_FOR_BUILD="-g -O2 -Wall" \
+%endif
   CFLAGS="$RPM_OPT_FLAGS" \
   ../binutils-%{binutils_pkgvers}/configure \
     --build=%_build --host=%_host \