move all plugin tests out of babel-core and into their appropriate folders

packages/babel-plugin-transform-es2015-function-name/test/fixtures/function-name/function-collision/actual.js

@@ -0,0 +1,19 @@
+function f() {
+  f;
+}
+
+{
+  let obj = {
+    f: function () {
+      f;
+    }
+  };
+}
+
+(function b() {
+  var obj = {
+    b: function () {
+      b;
+    }
+  };
+});

packages/babel-plugin-transform-es2015-function-name/test/fixtures/function-name/function-collision/expected.js

@@ -0,0 +1,19 @@
+function _f() {
+  _f;
+}
+
+{
+  let obj = {
+    f: function f() {
+      _f;
+    }
+  };
+}
+
+(function _b() {
+  var obj = {
+    b: function b() {
+      _b;
+    }
+  };
+});