Wrap gdb_agent_op_sizes by #ifndef IN_PROCESS_AGENT

Wrap gdb_agent_op_sizes by #ifndef IN_PROCESS_AGENT

Hi,
I see the following build warning with recent GCC built from mainline,

aarch64-none-linux-gnu-gcc -g -O2    -I. -I/home/yao/SourceCode/gnu/gdb/git/gdb/gdbserver -I/home/yao/SourceCode/gnu/gdb/git/gdb/gdbserver/../common -I/home/yao/SourceCode/gnu/gdb/git/gdb/gdbserver/../regformats -I/home/yao/SourceCode/gnu/gdb/git/gdb/gdbserver/.. -I/home/yao/SourceCode/gnu/gdb/git/gdb/gdbserver/../../include -I/home/yao/SourceCode/gnu/gdb/git/gdb/gdbserver/../gnulib/import -Ibuild-gnulib-gdbserver/import  -Wall -Wpointer-arith -Wformat-nonliteral -Wno-char-subscripts -Wempty-body -Wdeclaration-after-statement -Werror -DGDBSERVER  -DCONFIG_UST_GDB_INTEGRATION -fPIC -DIN_PROCESS_AGENT -fvisibility=hidden -c -o ax-ipa.o -MT ax-ipa.o -MMD -MP -MF .deps/ax-ipa.Tpo `echo " -Wall -Wpointer-arith -Wformat-nonliteral -Wno-char-subscripts -Wempty-body -Wdeclaration-after-statement " | sed "s/ -Wformat-nonliteral / -Wno-format-nonliteral /g"` /home/yao/SourceCode/gnu/gdb/git/gdb/gdbserver/ax.c
/home/yao/SourceCode/gnu/gdb/git/gdb/gdbserver/ax.c:73:28: error: 'gdb_agent_op_sizes' defined but not used [-Werror=unused-const-variable]
 static const unsigned char gdb_agent_op_sizes [gdb_agent_op_last] =
                            ^
cc1: all warnings being treated as errors

gdb_agent_op_sizes is only used in function is_goto_target, which is
defined inside #ifndef IN_PROCESS_AGENT.  This warning is not arch
specific, so GCC mainline for other targets should produce this warning
too, although this warning is triggered by enabling aarch64 fast
tracepoint.  The fix is to move gdb_agent_op_sizes to

gdb/gdbserver:

2015-09-21  Yao Qi  <yao.qi@linaro.org>

	* ax.c [!IN_PROCESS_AGENT] (gdb_agent_op_sizes): Define it.