TLS access support in cross- Linux GDB

[Ananthakrishna Sowda (asowda)]

TLS (thread-local storage) variable access in a core file is not supported for cross-Linux GDB.  Any attempt to print a _thread variable from a cross-target core file will result in following error:
"Cannot find thread-local variables on this target"

Pedro Alves in his closing remarks on – Bug 8210  “Linux core files should use linux-thread-db.c”  gave rationale for this limitation.
 https://sourceware.org/bugzilla/show_bug.cgi?id=8210

We have implemented a patch in GDB which enables TLS access for core files for cross-Linux builds.  The approach taken is to copy some code from glibc/nptl and build it as part of multi-arch GDB. 
We want to submit this patch to GDB community and get your feedback to improve it.
This is a heads-up for patch submission.