Update and add .gitignore's

This patch adds a bunch of generated files to gdb's gitignore files.
There are still a bunch of "stamp" files that are not ignored, but I
think the rule for them should be put in the top-level gitignore.

Users and developers are encouraged to build out-of-tree, but some
people prefer the simplicity to build in-tree, so it should be useful
for them.

gdb/ChangeLog:

	* .gitignore: Ignore more files.
	* data-directory/.gitignore: Likewise.

gdb/doc/ChangeLog:

	* .gitignore: New file.

gdb/gdbserver/ChangeLog:

	* .gitinore: Ignore more files.

gdb/testsuite/ChangeLog:

	* .gitignore: New file.

gdb/.gitignore

@@ -1,3 +1,8 @@
+/Makefile
+/build-gnulib
+/gdb-gdb.gdb
+/nm.h
+
 /version.c
 /xml-builtin.c
 
@@ -5,6 +10,7 @@
 /ada-lex.c
 /c-exp.c
 /cp-name-parser.c
+/d-exp.c
 /f-exp.c
 /gdb
 /gdbtui
@@ -18,3 +24,4 @@
 /observer.h
 /observer.inc
 /p-exp.c
+/rust-exp.c

gdb/ChangeLog

@@ -1,3 +1,8 @@
+2016-09-21  Simon Marchi  <simon.marchi@ericsson.com>
+
+	* .gitignore: Ignore more files.
+	* data-directory/.gitignore: Likewise.
+
 2016-09-21  Edjunior Barbosa Machado  <emachado@linux.vnet.ibm.com>
 
 	* rs6000-tdep.c (PPC_DQ): New macro.

gdb/data-directory/.gitignore

@@ -0,0 +1,5 @@
+/Makefile
+/guile
+/python
+/syscalls
+/system-gdbinit

gdb/doc/.gitignore

@@ -0,0 +1 @@
+/Makefile

gdb/doc/ChangeLog

@@ -1,3 +1,7 @@
+2016-09-21  Simon Marchi  <simon.marchi@ericsson.com>
+
+	* .gitignore: New file.
+
 2016-08-24  Simon Marchi  <simon.marchi@ericsson.com>
 
 	* gdb.texinfo (Input/Output): Mention possibility to unset

gdb/gdbserver/.gitignore

@@ -1,12 +1,26 @@
+/Makefile
+
 gdbreplay
 gdbserver
 libinproctrace.so
 
+build-gnulib-gdbserver
+build-libiberty-gdbserver
+
 amd64-avx-linux.c
+amd64-avx-mpx-linux.c
+amd64-avx512-linux.c
 amd64-linux.c
+amd64-mpx-linux.c
 i386-avx-linux.c
+i386-avx-mpx-linux.c
+i386-avx512-linux.c
 i386-linux.c
 i386-mmx-linux.c
+i386-mpx-linux.c
 reg-*.c
 version.c
+x32-avx-linux.c
+x32-avx512-linux.c
+x32-linux.c
 xml-builtin.c

gdb/gdbserver/ChangeLog

@@ -1,3 +1,7 @@
+2016-09-21  Simon Marchi  <simon.marchi@ericsson.com>
+
+	* .gitinore: Ignore more files.
+
 2016-09-21  Yao Qi  <yao.qi@linaro.org>
 
 	* linux-aarch32-low.c (arm_fill_gregset): Keep bits 20 to

gdb/testsuite/.gitignore

@@ -0,0 +1,9 @@
+/Makefile
+/lib/pdtrace
+/outputs
+
+/expect-read1
+/gdb.log
+/gdb.sum
+/read1.so
+/site.*

gdb/testsuite/ChangeLog

@@ -1,3 +1,7 @@
+2016-09-21  Simon Marchi  <simon.marchi@ericsson.com>
+
+	* .gitignore: New file.
+
 2016-09-21  Maciej W. Rozycki  <macro@imgtec.com>
 
 	* gdb.arch/mips16-thunks.exp: Use `standard_output_file'