[PATCH] microMIPS support (Linux signal trampolines)

[Joel Brobecker]

>  I'd like to get back to this change and review.  Here's the same code 
> regenerated against current trunk.  Can we please get consensus on changes 
> to tramp-frame.[ch]?
[...]
> 2014-09-28  Maciej W. Rozycki  <macro@codesourcery.com>
> 
> 	gdb/
> 	* tramp-frame.h (tramp_frame): Add validate member.
> 	* tramp-frame.c (tramp_frame_start): Validate trampoline before
> 	scanning.
> 	* mips-linux-tdep.c (MICROMIPS_INST_LI_V0): New macro.
> 	(MICROMIPS_INST_POOL32A, MICROMIPS_INST_SYSCALL): Likewise.
> 	(mips_linux_o32_sigframe): Initialize validate member.
> 	(mips_linux_o32_rt_sigframe): Likewise.
> 	(mips_linux_n32_rt_sigframe): Likewise.
> 	(mips_linux_n64_rt_sigframe): Likewise.
> 	(micromips_linux_o32_sigframe): New variable.
> 	(micromips_linux_o32_rt_sigframe): Likewise.
> 	(micromips_linux_n32_rt_sigframe): Likewise.
> 	(micromips_linux_n64_rt_sigframe): Likewise.
> 	(mips_linux_o32_sigframe_init): Handle microMIPS trampolines.
> 	(mips_linux_n32n64_sigframe_init): Likewise.
> 	(mips_linux_sigframe_validate): New function.
> 	(micromips_linux_sigframe_validate): Likewise.
> 	(mips_linux_init_abi): Install microMIPS trampoline unwinders.

Sorry again for the late review, Maciej.

This patch is pre-approved, with one tiny little request:
Can you add a quick one-liner comment as documentation for
all the new functions? For instance:

    /* Implement struct tramp_frame's "validate" method for [...]  */

    static int
    mips_linux_sigframe_validate (const struct tramp_frame *self,

Thank you!
-- 
Joel