Attach the elf section headers to the loaded kernel as metadata, so
they can easily be used by later post-processing.  When searching for
a compiled-in fdt blob, use the section headers to get the size and
location of the .dynsym section to do a symbol search.

This fixes a problem where the search could overshoot the symbol
table and wander into the string table.  Sometimes that was harmless
and sometimes it lead to spurious panic messages about an offset
bigger than the module size.
Correctly align the unwind tables. Without this clang may incorrectly align
them causing an alignment fault when producing a backtrace.
Tell the unwinder we can't unwind swi_entry. This fixes an infinite loop
when the kernel attempts to unwind through this function.

The .fnstart and .fnend in this function should be moved to macros but we
are currently missing an END macro on ARM.
Update how we read the stack pointer to work on both GCC and clang.
Fix a typo where db_printf was spelt printf.
- Clang doesn't understand the -mno-thumb-interwork. Only use it with gcc.
- We need to add "-mllvm -arm-enable-ehabi" to clangs CFLAGS when
  generating the unwind tables to tell it to add the required directives to
  the assembly it generates.
Kill this, it's not needed at this point and (hopefully) the parent
has correctly locked the ic/vap.
Add __aeabi_memcpy to libkern as clang may generate calls to it.
Add another register definition bit - whether to populate EVM or PLCP
data in the RX status descriptor.

Obtained from:	Qualcomm Atheros
Fix a typo in DPADD.
Finish portalfs removal.
Add more obsolete files.
Add 2 more obsolete files.
Correct a date, add an obsolete directory.
The kernel pmap is statically allocated, so there is really no need to
explicitly initialize its pm_root field to zero.

Sponsored by:	EMC / Isilon Storage Division
Bring back the comment on the sizing of the callout array that got
lost in r248031.

Requested by:	alc, alfred
Add three-stream EVM values.
Bump the EVM array size up to fit the AR9380 EVM entries.
Add a few new fields to the RX vendor radiotap header:

* a flags field that lets me know what's going on;
* the hardware ratecode, unmolested by conversion to a bitrate;
* the HAL rs_flags field, useful for debugging;
* specifically mark aggregate sub-frames.

This stuff sorely needs tidying up - it's missing some important
stuff (eg numdelims) and it would be nice to put the flags at the
beginning rather than at the end.

Tested:

* AR9380, STA mode, 2x2 HT40, monitoring RSSI and EVM values
Ports are no more exported via cvsup, remove cvsup examples and documentation refering to ports

MFC after:	2 days