Fix #3047

[July541]

It is because of the difference between hs-source-dirs: ./ and hs-source-dirs: ., take /user/project/Lib/A.hs as example,

	hs-source-dirs: ./	hs-source-dirs: .
project path	/user/project/./	/user/project/.
absolute project path	/user/project/	/user/project
canonicalized project path	/user/project	/user/project

The canonicalized project path will be used as the prefix for /user/project/Lib/A.hs

Canonicalized it to prevent dropping one more character.

[July541]

/cc @andrewufrank

[fendor]

Excuse me for this drive-by review, I was just looking at it and found the usage of canonicalizePath might be tricky.

[July541]

Excuse me for this drive-by review, I was just looking at it and found the usage of canonicalizePath might be tricky.

I'll try to evaluate the usage of canonicalizePath, at least find an alternative one.