wrap: Add failing unit test for fallback consistency

Dependency 'foo' is overriden with 'foo_dep' so using fallback variable
name 'bar_dep' should abort.

test cases/failing/106 fallback consistency/meson.build

@@ -0,0 +1,3 @@
+project('fallback consistency')
+
+dependency('foo')

test cases/failing/106 fallback consistency/subprojects/foo.wrap

@@ -0,0 +1,6 @@
+[wrap-file]
+source_url = http://host.invalid/foo.tar.gz
+source_filename = foo.tar.gz
+
+[provide]
+foo = bar_dep

test cases/failing/106 fallback consistency/subprojects/foo/meson.build

@@ -0,0 +1,6 @@
+project('sub')
+
+foo_dep = declare_dependency()
+meson.override_dependency('foo', foo_dep)
+
+bar_dep = declare_dependency()

test cases/failing/106 fallback consistency/test.json

@@ -0,0 +1,7 @@
+{
+  "stdout": [
+    {
+      "line": "test cases/failing/106 fallback consistency/meson.build:3:0: ERROR: Inconsistency: Subproject has overridden the dependency with another variable than 'bar_dep'"
+    }
+  ]
+}