Revert the header-sorting patch

Revert the header-sorting patch

Andreas Schwab and John Baldwin pointed out some bugs in the header
sorting patch; and I noticed that the output was not correct when
limited to a subset of files (a bug in my script).

So, I'm reverting the patch.  I may try again after fixing the issues
pointed out.

gdb/ChangeLog
2019-04-05  Tom Tromey  <tom@tromey.com>

	Revert the header-sorting patch.
	* ft32-tdep.c: Revert.
	* frv-tdep.c: Revert.
	* frv-linux-tdep.c: Revert.
	* frame.c: Revert.
	* frame-unwind.c: Revert.
	* frame-base.c: Revert.
	* fork-child.c: Revert.
	* findvar.c: Revert.
	* findcmd.c: Revert.
	* filesystem.c: Revert.
	* filename-seen-cache.h: Revert.
	* filename-seen-cache.c: Revert.
	* fbsd-tdep.c: Revert.
	* fbsd-nat.h: Revert.
	* fbsd-nat.c: Revert.
	* f-valprint.c: Revert.
	* f-typeprint.c: Revert.
	* f-lang.c: Revert.
	* extension.h: Revert.
	* extension.c: Revert.
	* extension-priv.h: Revert.
	* expprint.c: Revert.
	* exec.h: Revert.
	* exec.c: Revert.
	* exceptions.c: Revert.
	* event-top.c: Revert.
	* event-loop.c: Revert.
	* eval.c: Revert.
	* elfread.c: Revert.
	* dwarf2read.h: Revert.
	* dwarf2read.c: Revert.
	* dwarf2loc.c: Revert.
	* dwarf2expr.h: Revert.
	* dwarf2expr.c: Revert.
	* dwarf2-frame.c: Revert.
	* dwarf2-frame-tailcall.c: Revert.
	* dwarf-index-write.h: Revert.
	* dwarf-index-write.c: Revert.
	* dwarf-index-common.c: Revert.
	* dwarf-index-cache.h: Revert.
	* dwarf-index-cache.c: Revert.
	* dummy-frame.c: Revert.
	* dtrace-probe.c: Revert.
	* disasm.h: Revert.
	* disasm.c: Revert.
	* disasm-selftests.c: Revert.
	* dictionary.c: Revert.
	* dicos-tdep.c: Revert.
	* demangle.c: Revert.
	* dcache.h: Revert.
	* dcache.c: Revert.
	* darwin-nat.h: Revert.
	* darwin-nat.c: Revert.
	* darwin-nat-info.c: Revert.
	* d-valprint.c: Revert.
	* d-namespace.c: Revert.
	* d-lang.c: Revert.
	* ctf.c: Revert.
	* csky-tdep.c: Revert.
	* csky-linux-tdep.c: Revert.
	* cris-tdep.c: Revert.
	* cris-linux-tdep.c: Revert.
	* cp-valprint.c: Revert.
	* cp-support.c: Revert.
	* cp-namespace.c: Revert.
	* cp-abi.c: Revert.
	* corelow.c: Revert.
	* corefile.c: Revert.
	* continuations.c: Revert.
	* completer.h: Revert.
	* completer.c: Revert.
	* complaints.c: Revert.
	* coffread.c: Revert.
	* coff-pe-read.c: Revert.
	* cli-out.h: Revert.
	* cli-out.c: Revert.
	* charset.c: Revert.
	* c-varobj.c: Revert.
	* c-valprint.c: Revert.
	* c-typeprint.c: Revert.
	* c-lang.c: Revert.
	* buildsym.c: Revert.
	* buildsym-legacy.c: Revert.
	* build-id.h: Revert.
	* build-id.c: Revert.
	* btrace.c: Revert.
	* bsd-uthread.c: Revert.
	* breakpoint.h: Revert.
	* breakpoint.c: Revert.
	* break-catch-throw.c: Revert.
	* break-catch-syscall.c: Revert.
	* break-catch-sig.c: Revert.
	* blockframe.c: Revert.
	* block.c: Revert.
	* bfin-tdep.c: Revert.
	* bfin-linux-tdep.c: Revert.
	* bfd-target.c: Revert.
	* bcache.c: Revert.
	* ax-general.c: Revert.
	* ax-gdb.h: Revert.
	* ax-gdb.c: Revert.
	* avr-tdep.c: Revert.
	* auxv.c: Revert.
	* auto-load.c: Revert.
	* arm-wince-tdep.c: Revert.
	* arm-tdep.c: Revert.
	* arm-symbian-tdep.c: Revert.
	* arm-pikeos-tdep.c: Revert.
	* arm-obsd-tdep.c: Revert.
	* arm-nbsd-tdep.c: Revert.
	* arm-nbsd-nat.c: Revert.
	* arm-linux-tdep.c: Revert.
	* arm-linux-nat.c: Revert.
	* arm-fbsd-tdep.c: Revert.
	* arm-fbsd-nat.c: Revert.
	* arm-bsd-tdep.c: Revert.
	* arch-utils.c: Revert.
	* arc-tdep.c: Revert.
	* arc-newlib-tdep.c: Revert.
	* annotate.h: Revert.
	* annotate.c: Revert.
	* amd64-windows-tdep.c: Revert.
	* amd64-windows-nat.c: Revert.
	* amd64-tdep.c: Revert.
	* amd64-sol2-tdep.c: Revert.
	* amd64-obsd-tdep.c: Revert.
	* amd64-obsd-nat.c: Revert.
	* amd64-nbsd-tdep.c: Revert.
	* amd64-nbsd-nat.c: Revert.
	* amd64-nat.c: Revert.
	* amd64-linux-tdep.c: Revert.
	* amd64-linux-nat.c: Revert.
	* amd64-fbsd-tdep.c: Revert.
	* amd64-fbsd-nat.c: Revert.
	* amd64-dicos-tdep.c: Revert.
	* amd64-darwin-tdep.c: Revert.
	* amd64-bsd-nat.c: Revert.
	* alpha-tdep.c: Revert.
	* alpha-obsd-tdep.c: Revert.
	* alpha-nbsd-tdep.c: Revert.
	* alpha-mdebug-tdep.c: Revert.
	* alpha-linux-tdep.c: Revert.
	* alpha-linux-nat.c: Revert.
	* alpha-bsd-tdep.c: Revert.
	* alpha-bsd-nat.c: Revert.
	* aix-thread.c: Revert.
	* agent.c: Revert.
	* addrmap.c: Revert.
	* ada-varobj.c: Revert.
	* ada-valprint.c: Revert.
	* ada-typeprint.c: Revert.
	* ada-tasks.c: Revert.
	* ada-lang.c: Revert.
	* aarch64-tdep.c: Revert.
	* aarch64-ravenscar-thread.c: Revert.
	* aarch64-newlib-tdep.c: Revert.
	* aarch64-linux-tdep.c: Revert.
	* aarch64-linux-nat.c: Revert.
	* aarch64-fbsd-tdep.c: Revert.
	* aarch64-fbsd-nat.c: Revert.
	* aarch32-linux-nat.c: Revert.