tools: improve support for using compdb script from subrepos  (#18462)
tools: improve support for using compdb script from subrepos  (#18462)

Signed-off-by: Snow Pettersen <18824beaba694b0802bee531b635db27ba08e6bb@lyft.com>
lyft/envoy,envoyproxy/envoy,envoyproxy/envoy,lyft/envoy,envoyproxy/envoy,lyft/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy,lyft/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy,lyft/envoy,envoyproxy/envoy,lyft/envoy