Limit InputFile#findControlFile to package source root directory.
Limit InputFile#findControlFile to package source root directory.

This is an improvement that I noticed while investigating the
feasibility of fixing #8068.

Hansoft/meteor,mjmasn/meteor,mjmasn/meteor,Hansoft/meteor,Hansoft/meteor,Hansoft/meteor,mjmasn/meteor,mjmasn/meteor,Hansoft/meteor,mjmasn/meteor,mjmasn/meteor,Hansoft/meteor,mjmasn/meteor,Hansoft/meteor