cmd/compile: make dumpdepth a global again
cmd/compile: make dumpdepth a global again

Fixes indenting in debug output like -W.

Change-Id: Ia16b0bad47428cee71fe036c297731e841ec9ca0
Reviewed-on: https://go-review.googlesource.com/27924
Reviewed-by: Matthew Dempsky <e56ac2c500064424afac424d4b5e53bd0570a731@google.com>
Run-TryBot: Matthew Dempsky <e56ac2c500064424afac424d4b5e53bd0570a731@google.com>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>

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