runtime: fix TestCaller with -l=4
runtime: fix TestCaller with -l=4

Only the noinline pragma on testCallerFoo is needed to pass the test,
but the second pragma makes the test robust to future changes to the
inliner.

Change-Id: I80b384380c598f52e0382f53b59bb47ff196363d
Reviewed-on: https://go-review.googlesource.com/40877
Run-TryBot: David Lazar <859c8a6d485c34c743019c2e216e6c66f2ebb470@golang.org>
Reviewed-by: Austin Clements <7ea35d812706d9213868749011af1ed4fa2f6aa0@google.com>
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>

christopher-henderson/Go,cloudflare/go,nawawi/go,vsekhar/elastic-go,vsekhar/elastic-go,codestation/go,Cofyc/go,akutz/go,josharian/go,ImJasonH/go,vsekhar/elastic-go,josharian/go,vsekhar/elastic-go,codestation/go,derekmarcotte/go,vsekhar/elastic-go,josharian/go,Cofyc/go,vsekhar/elastic-go,codestation/go,derekmarcotte/go,ImJasonH/go,CAFxX/go,akutz/go,Cofyc/go,golang/go,josharian/go,golang/go,codestation/go,nawawi/go,nawawi/go,ImJasonH/go,polyverse-security/go,cloudflare/go,akutz/go,cloudflare/go,ImJasonH/go,josharian/go,CAFxX/go,derekmarcotte/go,golang/go,codestation/go,codestation/go,CAFxX/go,polyverse-security/go,akutz/go,akutz/go,Cofyc/go,CAFxX/go,cloudflare/go,golang/go,cloudflare/go,ImJasonH/go,nawawi/go,polyverse-security/go,nawawi/go,cloudflare/go,vsekhar/elastic-go,akutz/go,codestation/go,nawawi/go,CAFxX/go,golang/go,derekmarcotte/go,derekmarcotte/go,cloudflare/go,polyverse-security/go,nawawi/go,derekmarcotte/go,ImJasonH/go,derekmarcotte/go,polyverse-security/go,ImJasonH/go,CAFxX/go,golang/go,ImJasonH/go,Cofyc/go,polyverse-security/go,nawawi/go,CAFxX/go,derekmarcotte/go,polyverse-security/go,golang/go,akutz/go,CAFxX/go,Cofyc/go,codestation/go,josharian/go,josharian/go,cloudflare/go,Cofyc/go,akutz/go,vsekhar/elastic-go,polyverse-security/go,golang/go,josharian/go,Cofyc/go