cmd/govim: test introducing diagnostics in locally replaced dependencies

When using a locally replaced dependency it isn't monitored by gopls,
see https://golang.org/issues/36745.

This change adds a test that verifies that we do get diagnostics from
gopls when introducing errors in a replaced dependency.

cmd/govim/testdata/scenario_default/quickfix_replaced_dep.txt

@@ -0,0 +1,63 @@
+# Test that we get diagnostics for edits in a locally replaced dependency
+#
+# The scenario involves having a locally replaced dependency in go.mod.
+# When there is an error introduced into the local copy it should produce
+# a diagnostic (see https://golang.org/issues/36745).
+
+skip 'Pending fix for golang.org/issues/36745'
+
+# Open dependency via GoToDef
+vim ex 'e main.go'
+vim ex 'call cursor(6,11)'
+vim ex 'GOVIMGoToDef'
+errlogmatch '&protocol\.DidOpenTextDocumentParams\{\n\S+:\s+TextDocument: protocol.TextDocumentItem{URI:"file://'$WORK/p/blah.go
+
+# Add some nonsense to introduce a compile error
+vim call append '[3, "asd"]'
+
+# Expect the error to be reported
+vimexprwait error.golden GOVIMTest_getqflist()
+
+# Assert that we have received no error (Type: 1) or warning (Type: 2) log messages
+# Disabled pending resolution to https://github.com/golang/go/issues/34103
+# errlogmatch -start -count=0 'LogMessage callback: &protocol\.LogMessageParams\{Type:(1|2), Message:".*'
+
+-- go.mod --
+module a
+
+go 1.12
+
+replace example.com/blah => ./p
+
+require example.com/blah v1.0.0
+-- main.go --
+package main
+
+import "example.com/blah"
+
+func main() {
+	_ = blah.Name
+}
+-- p/go.mod --
+module example.com/blah
+
+go 1.12
+-- p/blah.go --
+package blah
+
+const Name = "example.com/blah"
+-- error.golden --
+[
+  {
+    "bufname": "p/blah.go",
+    "col": 1,
+    "lnum": 4,
+    "module": "",
+    "nr": 0,
+    "pattern": "",
+    "text": "expected declaration, found asd",
+    "type": "",
+    "valid": 1,
+    "vcol": 0
+  }
+]