Build GDB in native toolchain as a C application

As already described in previous commits, for this release GDB has to be
built as a C application. However there are two ways how these build scripts
build native toolchain:

1) As an additional step when building cross-toolchain
2) As a normal GDB when building native toolchain

Previous commit fixed case 1), but not the case 2). This is corrected in
this commit.

Signed-off-by: Anton Kolesov <[email protected]>

Author: anthony-kolesov

build-uclibc.sh

@@ -584,8 +584,18 @@ then
     build_expat $toolchain_build_dir/_download_tmp uclibc_stage2
 fi
 
+# See comment for "native GDB" being built later. If whole toolchain is native,
+# then this step is itself building a native GDB, hence same machinations with
+# disable-build-with-cxx are required.
+if [ $IS_NATIVE = yes ]; then
+    cxx_build=--disable-build-with-cxx
+else
+    cxx_build=
+fi
+
 build_dir_init gdb
-configure_uclibc_stage2 gdb gdb --disable-ld --disable-gas --disable-binutils
+configure_uclibc_stage2 gdb gdb --disable-ld --disable-gas --disable-binutils \
+    $cxx_build
 make_target building all
 make_target installing ${HOST_INSTALL}-gdb $stripprog_opt
 if [ "$DO_PDF" = "--pdf" ]