proc/native/freebsd: verify compatiblity with current go-tip (which will become Go 1.14)

[aarzilli]

Go 1.14 uses a new system to preempt goroutines non-cooperatively by sending a SIGURG signal to its own threads. This necessitates increased rigour in signal routing. We should verify that this doesn't expose latent bugs in the freebsd native backend before Go 1.14/Delve 1.4.0 is released.

cc @rayrapetyan

[rayrapetyan]

Currently it fails couple:

FAIL: TestIssue411
support.go:246: enabling recording for github.com/go-delve/delve/pkg/terminal.TestIssue411
command_test.go:105: output of "break math.go:8": ""
command_test.go:106: Error executing : Location "math.go:8" ambiguous: /ara/devel/go/src/github.com/go-delve/delve/_fixtures/math.go, /home/robert/sdk/gotip/src/runtime/internal/math/math.go…

FAIL: Test1ClientServer_traceContinue
FAIL: Test1ClientServer_traceContinue2
FAIL: TestDisasm

I believe first and last one should be common fails in all envs (please confirm). I can take care of the rest two.

[aarzilli]

Check out #1727 for fixes for os independent fixes for 1.14.

[derekparker]

I think we can close this one. @aarzilli please reopen if I'm mistaken.