[R] Import of S3 methods from bit64

[MichaelChirico]

arrow/r/NAMESPACE

Lines 430 to 431 in 62cdda9

	importFrom(bit64,print.integer64)
	importFrom(bit64,str.integer64)

From the next release (2027) of {bit64}, we will un-export S3 methods such as these. If S3 dispatch is not working for some reason, please file a bug and we can work on a fix or canonical workaround.

[MichaelChirico]

Glancing at the blame, it seems the original bug did not rely on this imported value at all, it was just about adding any name as an import from {bit64}.

https://issues.apache.org/jira/browse/ARROW-3647