eskip: re-generate parser

[AlexanderYastrebov]

go tool cover fails for eskip package:

$ go test ./eskip/ -coverprofile=.coverprofile && go tool cover -func .coverprofile
ok      github.com/zalando/skipper/eskip        0.026s  coverage: 88.2% of statements
cover: inconsistent NumStmt: changed from 1 to 2

this apparently happens due to malformed .coverprofile containing non-go files

$ cut -d: -f1 .coverprofile | grep -v -F '.go' | sort -u
github.com/zalando/skipper/eskip/parser.y
github.com/zalando/skipper/eskip/yaccpar
mode

added by line directives in generated parser.go.

The problem looks similar to the issue golang/go#45361.

To fix the problem updated go:generate directive to omit line directives (-l) and parsing tables (-v "") and re-generated the parser:

$ rm $(which goyacc)
$ go install golang.org/x/tools/cmd/goyacc
$ go generate ./eskip

Benchmark results did not change after re-generate:

name               old time/op    new time/op    delta
ParsePredicates-8    4.58µs ± 7%    4.42µs ± 0%   ~     (p=0.064 n=10+8)
LBBackendString-8    2.40µs ±12%    2.53µs ±11%   ~     (p=0.060 n=10+10)

name               old alloc/op   new alloc/op   delta
ParsePredicates-8      744B ± 0%      744B ± 0%   ~     (all equal)
LBBackendString-8    4.65kB ± 0%    4.65kB ± 0%   ~     (all equal)

name               old allocs/op  new allocs/op  delta
ParsePredicates-8      35.0 ± 0%      35.0 ± 0%   ~     (all equal)
LBBackendString-8      12.0 ± 0%      12.0 ± 0%   ~     (all equal)

[RomanZavodskikh]

👍

[MustafaSaber]

👍