Every one of the oracle's query modes needs to have typed ASTs
available, at least transiently, so that the -pos flag can be
interpreted. (The only mode that doesn't need the -pos flag
is callgraph, but that needs PTA.) So we hard-code it to true.
This change fixes a bug in the 'implements' query that causes
-pos parsing to fail. (This wasn't exposed by the tests
because they are degenerate in that the query always occurs in
the main package, which is specified ad-hoc, i.e. as a source
file not an import path. That's unfortunate, but this
change renders the distinction uninteresting in future.)
R=crawshaw, dominik.honnef
CC=golang-dev
https://golang.org/cl/13334050
d38c09ed22