Record total number of relocations, pcdata, automatics, funcdata and files in
object file and use these numbers in the linker to allocate contiguous
slices to later be filled by the defined symbols.

name       old secs    new secs    delta
LinkCmdGo   0.52 ± 3%   0.49 ± 3%  -4.21%   (p=0.000 n=91+92)
LinkJuju    4.48 ± 4%   4.21 ± 7%  -6.08%  (p=0.000 n=96+100)

name       old MaxRSS  new MaxRSS  delta
LinkCmdGo   122k ± 2%   120k ± 4%  -1.66%   (p=0.000 n=98+93)
LinkJuju    799k ± 5%   865k ± 8%  +8.29%   (p=0.000 n=89+99)

GOGC=off

name       old secs    new secs    delta
LinkCmdGo   0.42 ± 2%   0.41 ± 0%  -2.98%    (p=0.000 n=89+70)
LinkJuju    3.61 ± 0%   3.52 ± 1%  -2.46%    (p=0.000 n=80+89)

name       old MaxRSS  new MaxRSS  delta
LinkCmdGo   130k ± 1%   128k ± 1%  -1.33%  (p=0.000 n=100+100)
LinkJuju   1.00M ± 0%  0.99M ± 0%  -1.70%  (p=0.000 n=100+100)

Change-Id: Ie08f6ccd4311bb78d8950548c678230a58635c73
Reviewed-on: https://go-review.googlesource.com/21026Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>