gdb: Remove vec.{c,h} and update code to not include vec.h

Removes vec.c and vec.h from the source tree, and remove all the
remaining includes of vec.h.  There should be no user visible changes
after this commit.

I did have a few issues rebuilding GDB after applying this patch due
to cached dependencies, I found that running this command in the build
directory resolved my build issues without requiring a 'make clean':

    rm -fr gdb/gdbserver/gdbsupport/.deps/

gdb/ChangeLog:

	* Makefile.in: Remove references to vec.h and vec.c.
	* aarch64-tdep.c: No longer include vec.h.
	* ada-lang.c: Likewise.
	* ada-lang.h: Likewise.
	* arm-tdep.c: Likewise.
	* ax.h: Likewise.
	* breakpoint.h: Likewise.
	* charset.c: Likewise.
	* cp-support.h: Likewise.
	* dtrace-probe.c: Likewise.
	* dwarf2read.c: Likewise.
	* extension.h: Likewise.
	* gdb_bfd.c: Likewise.
	* gdbsupport/gdb_vecs.h: Likewise.
	* gdbsupport/vec.c: Remove.
	* gdbsupport/vec.h: Remove.
	* gdbthread.h: Likewise.
	* guile/scm-type.c: Likewise.
	* inline-frame.c: Likewise.
	* machoread.c: Likewise.
	* memattr.c: Likewise.
	* memrange.h: Likewise.
	* namespace.h: Likewise.
	* nat/linux-btrace.h: Likewise.
	* osdata.c: Likewise.
	* parser-defs.h: Likewise.
	* progspace.h: Likewise.
	* python/py-type.c: Likewise.
	* record-btrace.c: Likewise.
	* rust-exp.y: Likewise.
	* solib-target.c: Likewise.
	* stap-probe.c: Likewise.
	* target-descriptions.c: Likewise.
	* target-memory.c: Likewise.
	* target.h: Likewise.
	* varobj.c: Likewise.
	* varobj.h: Likewise.
	* xml-support.h: Likewise.

gdb/gdbserver/ChangeLog:

	* Makefile.in: Remove references to vec.c.

Change-Id: I0c91d7170bf1b5e992a387fcd9fe4f2abe343bb5

gdb/python/py-type.c

@@ -26,7 +26,6 @@
 #include "demangle.h"
 #include "objfiles.h"
 #include "language.h"
-#include "gdbsupport/vec.h"
 #include "typeprint.h"
 
 typedef struct pyty_type_object