MFC: 266171, 266174

Extend the size of the function or symbol that can be annotated.

Update the amount of data we can collect for hwpmc(4) by default
to work with modern processors and available memory.
MFC: 266166

Extend the size of the function or symbol that can be annotated.
MFC: 266209

Add a command line argument (-l) to end event collection after some
number of seconds.  The number of seconds may be a fraction.

Submitted by:	Julien Charbon <jcharbon@versign.com>
Relnotes:	yes
MFC r263446

Update hwpmc to support core events for Atom Silvermont microarchitecture.
(Model 0x4D as per Intel document 330061-001 01/2014)
MFC r266782:

In r218101 I have not changed properly the futex syscall definition.
Some Linux futex ops atomically verifies that the futex address uaddr
(uval) contains the value val. Comparing signed uval and unsigned val
may lead to an unexpected result, mostly to a deadlock.

So copyin uaddr to an unsigned int to compare the parameters correctly.

While here change ktr records to print parameters in more readable format.
MFC: r266270

Remove some unused variables.
Merge remote-tracking branch 'freebsd/stable/10' into hardened/10/aslr