test: Match gccgo error messages.
explicit.go:36:4: error: incompatible types in assignment (need explicit conversion)
explicit.go:41:4: error: incompatible types in assignment (type has no methods)
explicit.go:42:4: error: incompatible types in assignment (need explicit conversion)
explicit.go:45:5: error: incompatible types in assignment (need explicit conversion; missing method ‘N’)
explicit.go:48:9: error: invalid type conversion (need explicit conversion; missing method ‘N’)
explicit.go:51:4: error: incompatible types in assignment
explicit.go:51:7: error: invalid type conversion (need explicit conversion)
explicit.go:57:10: error: impossible type assertion: type does not implement interface (type has no methods)
explicit.go:62:10: error: impossible type assertion: type does not implement interface (incompatible type for method ‘M’ (different number of parameters))
explicit.go:67:5: error: incompatible type in initialization (type has no methods)
explicit.go:68:5: error: incompatible type in initialization (incompatible type for method ‘M’ (different number of parameters))
explicit.go:70:11: error: invalid type conversion (type has no methods)
explicit.go:71:11: error: invalid type conversion (incompatible type for method ‘M’ (different number of parameters))
R=rsc
CC=golang-dev
https://golang.org/cl/
2139044