add test for name resolution shadowing

prost-reflect/tests/data/name_resolution4.yml

@@ -0,0 +1,18 @@
+file:
+- name: dep.proto
+  package: foo.bar
+  messageType:
+  - name: FooBar
+- name: root.proto
+  package: com.foo.bar
+  dependency:
+  - dep.proto
+  messageType:
+  - name: Foo
+    field:
+    - name: foobar
+      number: 1
+      label: LABEL_OPTIONAL
+      typeName: foo.FooBar
+      jsonName: foobar
+  syntax: proto3

prost-reflect/tests/main.rs

@@ -132,6 +132,7 @@ check_err!(invalid_service_type3);
 check_err!(name_resolution1);
 check_err!(name_resolution2);
 check_ok!(name_resolution3);
+check_err!(name_resolution4);
 check_err!(name_collision1);
 check_err!(name_collision2);
 check_err!(name_collision3);

prost-reflect/tests/snapshots/main__name_resolution4.snap

@@ -0,0 +1,11 @@
+---
+source: prost-reflect/tests/main.rs
+assertion_line: 79
+expression: actual
+---
+causes: []
+help: "'foo.FooBar' is is resolved to 'com.foo.FooBar', which is not defined. The innermost scope is searched first in name resolution. Consider using a leading '.'(i.e., '.foo.FooBar') to start from the outermost scope."
+labels: []
+message: "name 'foo.FooBar' is shadowed"
+related: []
+severity: error