Avoid -Wnarrowing warnings in struct tramp_frame instances

Avoid -Wnarrowing warnings in struct tramp_frame instances

This avoids -Wnarrowing warnings in struct tramp_frame instances,
replacing uses of -1 with a new ULONGEST_MAX.  It also redefined
TRAMP_SENTINEL_INSN to avoid the same warning.

gdb/ChangeLog
2018-08-27  Tom Tromey  <tom@tromey.com>

	* tramp-frame.h (TRAMP_SENTINEL_INSN): Redefine.
	* tilegx-linux-tdep.c (tilegx_linux_rt_sigframe): Use
	ULONGEST_MAX.
	* tic6x-linux-tdep.c (tic6x_linux_rt_sigreturn_tramp_frame): Use
	ULONGEST_MAX.
	* sparc64-linux-tdep.c (sparc64_linux_rt_sigframe): Use
	ULONGEST_MAX.
	* sparc-linux-tdep.c (sparc32_linux_sigframe)
	(sparc32_linux_rt_sigframe): Use ULONGEST_MAX.
	* ppc-nbsd-tdep.c (ppcnbsd_sigtramp, ppcnbsd2_sigtramp): Use
	ULONGEST_MAX.
	* ppc-linux-tdep.c (ppc32_linux_sigaction_tramp_frame)
	(ppc64_linux_sigaction_tramp_frame)
	(ppc32_linux_sighandler_tramp_frame)
	(ppc64_linux_sighandler_tramp_frame): Use ULONGEST_MAX.
	* nios2-linux-tdep.c (nios2_r1_linux_rt_sigreturn_tramp_frame)
	(nios2_r2_linux_rt_sigreturn_tramp_frame): Use ULONGEST_MAX.
	* mn10300-linux-tdep.c (am33_linux_sigframe)
	(am33_linux_rt_sigframe): Use ULONGEST_MAX.
	* mips64-obsd-tdep.c (mips64obsd_sigframe): Use ULONGEST_MAX.
	* mips-linux-tdep.c (mips_linux_o32_sigframe)
	(mips_linux_o32_rt_sigframe, mips_linux_n32_rt_sigframe)
	(mips_linux_n64_rt_sigframe, micromips_linux_o32_sigframe)
	(micromips_linux_o32_rt_sigframe, micromips_linux_n32_rt_sigframe)
	(micromips_linux_n64_rt_sigframe): Use ULONGEST_MAX.
	* mips-fbsd-tdep.c (mips_fbsd_sigframe, mipsn32_fbsd_sigframe)
	(mips64_fbsd_sigframe): Use ULONGEST_MAX.
	* microblaze-linux-tdep.c
	(microblaze_linux_sighandler_tramp_frame): Use ULONGEST_MAX.
	* i386-nbsd-tdep.c (i386nbsd_sigtramp_sc16, i386nbsd_sigtramp_sc2)
	(i386nbsd_sigtramp_si2, i386nbsd_sigtramp_si31)
	(i386nbsd_sigtramp_si4): Use ULONGEST_MAX.
	* hppa-nbsd-tdep.c (hppanbsd_sigtramp_si4): Use ULONGEST_MAX.
	* common/common-types.h (ULONGEST_MAX): New define.
	(CORE_ADDR_MAX): Fix formatting.
	* bfin-linux-tdep.c (bfin_linux_sigframe): Use ULONGEST_MAX.
	* arm-obsd-tdep.c (armobsd_sigframe): Use ULONGEST_MAX.
	* arm-linux-tdep.c (arm_linux_sigreturn_tramp_frame)
	(arm_linux_rt_sigreturn_tramp_frame)
	(arm_eabi_linux_sigreturn_tramp_frame)
	(arm_eabi_linux_rt_sigreturn_tramp_frame)
	(thumb2_eabi_linux_sigreturn_tramp_frame)
	(thumb2_eabi_linux_rt_sigreturn_tramp_frame)
	(arm_linux_restart_syscall_tramp_frame)
	(arm_kernel_linux_restart_syscall_tramp_frame): Use ULONGEST_MAX.
	* arm-fbsd-tdep.c (arm_fbsd_sigframe): Use ULONGEST_MAX.
	* aarch64-linux-tdep.c (aarch64_linux_rt_sigframe): Use
	ULONGEST_MAX.
	* aarch64-fbsd-tdep.c (aarch64_fbsd_sigframe): Use ULONGEST_MAX.