Excluding methods dispatched on the types defined in Main

[aminya]

In my tests, I defined a couple of types to test my package, however, SnoopCompile generates precompile sentences for these.
We should exclude those from appearing in the precompilition files.
aminya/AcuteML.jl@3e9210a

[aminya]

SnoopCompile.parcel seems to do this.

[timholy]

Yes, I think this working the way it should.