html/template: prefix the internally-used FuncMap values with an underscore
html/template: prefix the internally-used FuncMap values with an underscore

This makes these names even less likely to collide with a real user-defined function.

Fixes #13852.

Change-Id: If5a8562c6797ced19c355c7ab2c86fc4401a8674
Reviewed-on: https://go-review.googlesource.com/21490
Run-TryBot: Rob Pike <4dc7c9ec434ed06502767136789763ec11d2c4b7@golang.org>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Andrew Gerrand <395a7d33bec8475c9b83b7d440f141bcbd994aa5@golang.org>

suncycheng/go,ImJasonH/go,akutz/go,josharian/go,cloudflare/go,cloudflare/go,ganboing/go-esx,codestation/go,vsekhar/elastic-go,suncycheng/go,suncycheng/go,derekmarcotte/go,goodlang/good,theif519/go,polyverse-security/go,josharian/go,derekmarcotte/go,linux-on-ibm-z/go,4ad/go,codestation/go,momchil-velikov/go,derekmarcotte/go,linux-on-ibm-z/go,4ad/go,Cofyc/go,CAFxX/go,polyverse-security/go,polyverse-security/go,suncycheng/go,Cofyc/go,momchil-velikov/go,CAFxX/go,CAFxX/go,4ad/go,ganboing/go-esx,vanloswang/go,Cofyc/go,theif519/go,golang/go,akutz/go,polyverse-security/go,cloudflare/go,miolini/go,momchil-velikov/go,codestation/go,CAFxX/go,goodlang/good,christopher-henderson/Go,goodlang/good,vanloswang/go,cloudflare/go,goodlang/good,josharian/go,vanloswang/go,linux-on-ibm-z/go,momchil-velikov/go,momchil-velikov/go,ImJasonH/go,theif519/go,josharian/go,josharian/go,akutz/go,miolini/go,codestation/go,golang/go,CAFxX/go,vsekhar/elastic-go,akutz/go,vsekhar/elastic-go,vsekhar/elastic-go,ganboing/go-esx,linux-on-ibm-z/go,ImJasonH/go,4ad/go,miolini/go,suncycheng/go,theif519/go,Cofyc/go,miolini/go,nawawi/go,vsekhar/elastic-go,polyverse-security/go,ImJasonH/go,nawawi/go,codestation/go,4ad/go,ImJasonH/go,vsekhar/elastic-go,derekmarcotte/go,golang/go,4ad/go,vanloswang/go,nawawi/go,derekmarcotte/go,Cofyc/go,theif519/go,Cofyc/go,vanloswang/go,nawawi/go,goodlang/good,nawawi/go,josharian/go,theif519/go,momchil-velikov/go,akutz/go,ganboing/go-esx,Cofyc/go,vanloswang/go,goodlang/good,miolini/go,ganboing/go-esx,polyverse-security/go,derekmarcotte/go,polyverse-security/go,linux-on-ibm-z/go,golang/go,josharian/go,golang/go,ImJasonH/go,codestation/go,miolini/go,cloudflare/go,4ad/go,CAFxX/go,cloudflare/go,goodlang/good,ganboing/go-esx,polyverse-security/go,nawawi/go,cloudflare/go,ganboing/go-esx,suncycheng/go,golang/go,ImJasonH/go,vsekhar/elastic-go,miolini/go,akutz/go,golang/go,cloudflare/go,codestation/go,vsekhar/elastic-go,momchil-velikov/go,suncycheng/go,goodlang/good,vanloswang/go,golang/go,ganboing/go-esx,theif519/go,josharian/go,nawawi/go,derekmarcotte/go,akutz/go,derekmarcotte/go,CAFxX/go,suncycheng/go,vanloswang/go,linux-on-ibm-z/go,4ad/go,ImJasonH/go,akutz/go,momchil-velikov/go,linux-on-ibm-z/go,CAFxX/go,theif519/go,miolini/go,nawawi/go,Cofyc/go,codestation/go,linux-on-ibm-z/go