cmd/compile: give TLS relocations a name when dumping assembly
cmd/compile: give TLS relocations a name when dumping assembly

Before:

	...
	0x00d0 ff ff ff e8 00 00 00 00 e9 23 ff ff ff cc cc cc  .........#......
	rel 5+4 t=14 +0
	rel 82+4 t=13 runtime.writeBarrier+0
	...

After:

	...
	0x00d0 ff ff ff e8 00 00 00 00 e9 23 ff ff ff cc cc cc  .........#......
	rel 5+4 t=14 TLS+0
	rel 82+4 t=13 runtime.writeBarrier+0
	...

Change-Id: Ibdaf694581b5fd5fb87fa8ce6a792f3eb4493622
Reviewed-on: https://go-review.googlesource.com/21545
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>

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