runtime: add interface microbenchmarks
2011 Mac Mini, Core i5 @ 2.3Ghz
BenchmarkConvT2E
50000000 40.4 ns/op
BenchmarkConvT2EBig
20000000 107 ns/op
BenchmarkConvT2I
100000000 28.9 ns/op
BenchmarkConvI2E
500000000 5.93 ns/op
BenchmarkConvI2I
100000000 19.0 ns/op
BenchmarkAssertE2T
100000000 14.1 ns/op
BenchmarkAssertE2TBig
100000000 17.8 ns/op
BenchmarkAssertE2I
100000000 21.3 ns/op
BenchmarkAssertI2T
100000000 14.3 ns/op
BenchmarkAssertI2I
100000000 20.8 ns/op
BenchmarkAssertI2E
500000000 5.58 ns/op
Pandaboard, 2 x Omap4 @ 1.2Ghz
BenchmarkConvT2E
10000000 215 ns/op
BenchmarkConvT2EBig
1000000 3697 ns/op
BenchmarkConvT2I
5000000 666 ns/op
BenchmarkConvI2E
50000000 42.4 ns/op
BenchmarkConvI2I
5000000 489 ns/op
BenchmarkAssertE2T
20000000 90.0 ns/op
BenchmarkAssertE2TBig
20000000 91.6 ns/op
BenchmarkAssertE2I
5000000 515 ns/op
BenchmarkAssertI2T
20000000 124 ns/op
BenchmarkAssertI2I
5000000 517 ns/op
BenchmarkAssertI2E
50000000 47.2 ns/op
BenchmarkAssertE2E
50000000 42.7 ns/op
R=minux.ma, rsc, fullung, bsiegert, dsymonds
CC=golang-dev
https://golang.org/cl/
5777048