panic: *ssa.Phi during rows declaration without assignment

[nelsam]

sqlrows panics when parsing the following code:

var rows *sql.Rows
if foo {
    rows, err = queryFoo()
} else {
    rows, err = queryBar()
}
if err != nil { return err }
defer rows.Close()

After digging in, it seems this is because var rows *sql.Rows comes in as an *ssa.Phi rather than an *ssa.Extract.