cmd/internal/obj/x86: cleanup
cmd/internal/obj/x86: cleanup

Remove duplicate vars, commented out code  and duplicate lines.
When choosing between 2 aliases, on with more uses was chosen.

Change-Id: I7bc15f1693de3f6d378cef9c09469970a659db40
Reviewed-on: https://go-review.googlesource.com/29152
Run-TryBot: Ilya Tocar <112830fdd81fb6e3c10661fec6ab883a8a8a909f@intel.com>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Keith Randall <8c99c3a9284e493be632950b84cd789d08ed3e9d@golang.org>

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