runtime: simplify getargp
runtime: simplify getargp

Change-Id: I9ed62e8a6d8b9204c18748efd7845adabf3460b9
Reviewed-on: https://go-review.googlesource.com/28775
Run-TryBot: Josh Bleecher Snyder <cdc248cc4d32e4fbfe04e45228163bcecd48a0b9@gmail.com>
Reviewed-by: Keith Randall <8c99c3a9284e493be632950b84cd789d08ed3e9d@golang.org>
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>

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