tree: sync httprouter update

[thinkerou]

from httprouter:
julienschmidt/httprouter@e746cd6
julienschmidt/httprouter@6289311

[codecov]

Codecov Report

Merging #2172 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #2172      +/-   ##
==========================================
+ Coverage   98.62%   98.62%   +<.01%     
==========================================
  Files          40       40              
  Lines        2249     2252       +3     
==========================================
+ Hits         2218     2221       +3     
  Misses         16       16              
  Partials       15       15

Impacted Files	Coverage Δ
tree.go	100% <100%> (ø)	⬆️

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[appleboy]

Add benchmark:

#GithubAPI Routes: 203
   Aero: 477544 Bytes
   Echo: 100088 Bytes
   Gin: 58512 Bytes

#GPlusAPI Routes: 13
   Aero: 26552 Bytes
   Echo: 9688 Bytes
   Gin: 4384 Bytes

#ParseAPI Routes: 26
   Aero: 29304 Bytes
   Echo: 11664 Bytes
   Gin: 7776 Bytes

#Static Routes: 157
   Aero: 34536 Bytes
   Echo: 80328 Bytes
   Gin: 34936 Bytes

goos: darwin
goarch: amd64
pkg: github.com/julienschmidt/go-http-routing-benchmark

BenchmarkAero_Param        	19066371	        63.7 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_Param        	12781616	        89.5 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_Param         	15486387	        75.5 ns/op	       0 B/op	       0 allocs/op
BenchmarkAero_Param5       	13042006	        91.0 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_Param5       	 5753504	       203 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_Param5        	 9591780	       127 ns/op	       0 B/op	       0 allocs/op
BenchmarkAero_Param20      	27214122	        40.8 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_Param20      	 2114517	       564 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_Param20       	 3789758	       317 ns/op	       0 B/op	       0 allocs/op
BenchmarkAero_ParamWrite   	11472574	       104 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_ParamWrite   	 5577409	       206 ns/op	       8 B/op	       1 allocs/op
BenchmarkGin_ParamWrite    	 8375779	       143 ns/op	       0 B/op	       0 allocs/op
BenchmarkAero_GithubStatic 	17713472	        65.1 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_GithubStatic 	10947165	       110 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_GithubStatic  	12220562	        90.5 ns/op	       0 B/op	       0 allocs/op
BenchmarkAero_GithubParam  	 9152474	       123 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_GithubParam  	 5408626	       209 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_GithubParam   	 7706559	       145 ns/op	       0 B/op	       0 allocs/op
BenchmarkAero_GithubAll    	   49484	     24083 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_GithubAll    	   30248	     40352 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_GithubAll     	   39904	     30090 ns/op	       0 B/op	       0 allocs/op
BenchmarkAero_GPlusStatic  	23605906	        49.7 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_GPlusStatic  	14785716	        78.9 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_GPlusStatic   	15265910	        77.6 ns/op	       0 B/op	       0 allocs/op
BenchmarkAero_GPlusParam   	14595098	        79.8 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_GPlusParam   	 9785448	       122 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_GPlusParam    	13082052	        92.3 ns/op	       0 B/op	       0 allocs/op
BenchmarkAero_GPlus2Params 	10442065	       120 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_GPlus2Params 	 6500953	       180 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_GPlus2Params  	 9571652	       118 ns/op	       0 B/op	       0 allocs/op
BenchmarkAero_GPlusAll     	 1000000	      1135 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_GPlusAll     	  635904	      1848 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_GPlusAll      	  971122	      1268 ns/op	       0 B/op	       0 allocs/op
BenchmarkAero_ParseStatic  	20736540	        53.2 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_ParseStatic  	14566063	        79.6 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_ParseStatic   	15158078	        75.7 ns/op	       0 B/op	       0 allocs/op
BenchmarkAero_ParseParam   	17168784	        68.7 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_ParseParam   	11767852	        98.5 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_ParseParam    	16394192	        77.2 ns/op	       0 B/op	       0 allocs/op
BenchmarkAero_Parse2Params 	14465080	        82.0 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_Parse2Params 	 9124714	       134 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_Parse2Params  	12695834	        92.4 ns/op	       0 B/op	       0 allocs/op
BenchmarkAero_ParseAll     	  644544	      1913 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_ParseAll     	  408574	      3066 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_ParseAll      	  472464	      2336 ns/op	       0 B/op	       0 allocs/op
BenchmarkAero_StaticAll    	  104926	     11152 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_StaticAll    	   43567	     27307 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_StaticAll     	   54282	     21504 ns/op	       0 B/op	       0 allocs/op
PASS
ok  	github.com/julienschmidt/go-http-routing-benchmark	65.618s

[thinkerou]

better than #2153