[Patch, microblaze]: Add wdc.ext.clear and wdc.ext.flush insns

Added two new instructions, wdc.ext.clear and wdc.ext.flush,
to enable MicroBlaze to flush an external cache, which is
used with the new coherency support for multiprocessing.

Signed-off-by:nagaraju <nmekala@xilix.com>
Signed-off-by: David Holsgrove <david.holsgrove@xilinx.com>
[Patch, microblaze]: Add mlittle-endian and mbig-endian flags

Added support in gas for mlittle-endian and mbig-endian flags
as options.

Updated show usage for MicroBlaze specific assembler options
to include new entries.

Signed-off-by:nagaraju <nmekala@xilix.com>
Signed-off-by: David Holsgrove <david.holsgrove@xilinx.com>
[LOCAL GDB]: initial port of gdb6.5 microblaze core reading support

Added support for reading notes in linux core dumps
Support for reading of PRSTATUS and PSINFO information for rebuilding
".reg" sections of core dumps at run time.

Signed-off-by: David Holsgrove <david.holsgrove@petalogix.com>
Signed-off-by: Nathan Rossi <nathan.rossi@petalogix.com>
[LOCAL]: Disable the warning message for eh_frame_hdr

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
[LOCAL]: Fix relaxation of assembler resolved references
[LOCAL]: Fixup debug_loc sections after linker relaxation

Adds a new reloctype R_MICROBLAZE_32_NONE, used for passing
reloc info from the assembler to the linker when the linker
manages to fully resolve a local symbol reference.

This is a workaround for design flaws in the assembler to
linker interface with regards to linker relaxation.

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Signed-off-by: David Holsgrove <david.holsgrove@xilinx.com>
[LOCAL REVERT]: upstream change to garbage collection sweep causes mb regression

Upstream change for PR13177 now clears the def_regular during gc_sweep of a
section. (All other archs in binutils/bfd/elf32-*.c received an update
to a warning about unresolvable relocations - this warning is not present
in binutils/bfd/elf32-microblaze.c, but this warning check would not
prevent the error being seen)

The visible issue with this change is when running a c++ application
in Petalinux which links libstdc++.so for exception handling it segfaults
on execution.

This does not occur if static linking libstdc++.a, so its during the
relocations for a shared lib with garbage collection this occurs

Signed-off-by: David Holsgrove <david.holsgrove@xilinx.com>