internal/symbol: support package paths with hyphens
internal/symbol: support package paths with hyphens

parseRow is updated to support package paths with hyphens.

For golang/go#37102

Change-Id: I9ba6a9928a8f11779ff025cb68ca0c287506403f
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/340090
Trust: Julie Qiu <8d32267b6b4884cf35adeaccde2b6857ae11aace@golang.org>
Reviewed-by: Jonathan Amsterdam <e3d3698b2ccd5955e4adf250d0785062d0f9018b@google.com>

golang/pkgsite,golang/pkgsite,golang/pkgsite,golang/pkgsite