Move common handlers to sol2_init_abi

Move common handlers to sol2_init_abi

There's some overlap and duplication between 32 and 64-bit Solaris/SPARC
and x86 tdep files, in particular

        sol2_core_pid_to_str
	*_sol2_sigtramp_p
        sol2_skip_solib_resolver
        *_sol2_static_transform_name (forgotten on amd64)
        set_gdbarch_sofun_address_maybe_missing (likewise)

This patch avoids this by centralizing common code in sol2-tdep.c.
While sparc_sol2_pc_in_sigtramp and sparc_sol2_static_transform_name
were declared in the shared sparc-tdep.h, they were only used in Solaris
files.

Tested on amd64-pc-solaris2.11, i386-pc-solaris2.11,
sparcv9-sun-solaris2.11, and sparc-sun-solaris2.11, and
sparc64-unknown-linux-gnu.

	* amd64-sol2-tdep.c (amd64_sol2_sigtramp_p): Remove.
	(amd64_sol2_init_abi): Use sol2_sigtramp_p.
	Call sol2_init_abi.
 	Remove calls to set_gdbarch_skip_solib_resolver,
	set_gdbarch_core_pid_to_str.
	* i386-sol2-tdep.c (i386_sol2_sigtramp_p): Remove.
	(i386_sol2_static_transform_name): Remove.
	(i386_sol2_init_abi): Call sol2_init_abi.
	Remove calls to set_gdbarch_sofun_address_maybe_missing,
	set_gdbarch_static_transform_name,
	set_gdbarch_skip_solib_resolver, set_gdbarch_core_pid_to_str.
	Use sol2_sigtramp_p.
	* sol2-tdep.c (sol2_pc_in_sigtramp): New function.
	(sol2_sigtramp_p): New function.
	(sol2_static_transform_name): New function.
	(sol2_skip_solib_resolver, sol2_core_pid_to_str): Make static.
	(sol2_init_abi): New function.
	* sol2-tdep.h (sol2_sigtramp_p, sol2_init_abi): Declare.
	(sol2_skip_solib_resolver, sol2_core_pid_to_str): Remove.
	* sparc-sol2-tdep.c (sparc_sol2_pc_in_sigtramp): Remove.
	(sparc32_sol2_sigtramp_frame_sniffer): Just call sol2_sigtramp_p.
	(sparc_sol2_static_transform_name): Remove.
	(sparc32_sol2_init_abi): Call sol2_init_abi.
	Remove calls to set_gdbarch_sofun_address_maybe_missing,
	set_gdbarch_static_transform_name,
	set_gdbarch_skip_solib_resolver,
	set_gdbarch_core_pid_to_str.
	* sparc-tdep.h (sparc_sol2_pc_in_sigtramp)
	(sparc_sol2_static_transform_name): Remove
	* sparc64-sol2-tdep.c (sparc64_sol2_sigtramp_frame_sniffer): Just
	call sol2_sigtramp_p.
	(sparc64_sol2_init_abi): Call sol2_init_abi.
	Remove calls to set_gdbarch_sofun_address_maybe_missing,
	set_gdbarch_static_transform_name,
	set_gdbarch_skip_solib_resolver, set_gdbarch_core_pid_to_str.