gcc: Fix mangled patch

To quote Zhuang <qiuguang.zqg@alibaba-inc.com>:
"""
A few days ago, I tried to compile a gcc plugin with the toolchain from poky sdk.
It failed with errors about missing header files such as backend.h etc.

After investigation, I found that the problem was brought by a gcc patch:
0012-gcc-Fix-argument-list-too-long-error.patch (which is considered derived from the original patch)

- headers=`echo $(PLUGIN_HEADERS) $$(cd $(srcdir); echo *.h *.def) | tr ' ' '\012' | sort -u`; \
+ headers="$(sort $(PLUGIN_HEADERS) $$(cd $(srcdir); echo *.h *.def))"; \

It changes the commands of install-plugin, making the sorting taken effect before the shell globs.
Thus results in the header files under gcc $(srcdir) being not installed.

By checking log.do_install, we can find that the `headers=' statement to run is incorrect and will not work as expected:
headers="$(cd *.def) *.h ../../../../../../../work-shared/gcc-10.1.0-r0/gcc-10.1.0/gcc/../include/ansidecl.h ...

As the patch says,
"The PLUGIN_HEADERS is too long before sort, so the "echo" can't handle it, ..."
my suggestion is that we can simply take care of PLUGIN_HEADERS
using the original proposed sort.
"""

This fixes the gcc patch as proposed as it does appear its been
broken over time.

(From OE-Core rev: dce28d8ac7fbae487cb6674b91fe2b574036b26d)

(From OE-Core rev: cfa92a4d57f49188ca7b568e2003e4a11526fc95)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit 94eb5724b1)
Signed-off-by: Anuj Mittal <anuj.mittal@intel.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-devtools/gcc/gcc-9.3/0012-gcc-Fix-argument-list-too-long-error.patch

@@ -17,6 +17,10 @@ $(sort list) doesn't need this.
 Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
 Signed-off-by: Khem Raj <raj.khem@gmail.com>
 
+RP: gcc then added *.h and *.def additions to this list, breaking the original
+fix. Add the sort to the original gcc code, leaving the tr+sort to fix the original
+issue but include the new files too as reported by Zhuang <qiuguang.zqg@alibaba-inc.com>
+
 Upstream-Status: Pending
 ---
  gcc/Makefile.in | 2 +-
@@ -31,7 +35,7 @@ index fef6c4c61e3..57cf7804f0a 100644
  # files. All other files are flattened to a single directory.
  	$(mkinstalldirs) $(DESTDIR)$(plugin_includedir)
 -	headers=`echo $(PLUGIN_HEADERS) $$(cd $(srcdir); echo *.h *.def) | tr ' ' '\012' | sort -u`; \
-+	headers="$(sort $(PLUGIN_HEADERS) $$(cd $(srcdir); echo *.h *.def))"; \
++	headers=`echo $(sort $(PLUGIN_HEADERS)) $$(cd $(srcdir); echo *.h *.def) | tr ' ' '\012' | sort -u`; \
  	srcdirstrip=`echo "$(srcdir)" | sed 's/[].[^$$\\*|]/\\\\&/g'`; \
  	for file in $$headers; do \
  	  if [ -f $$file ] ; then \