Rename some test fixtures so they run properly. (#8265)

packages/babel-plugin-transform-modules-commonjs/test/fixtures/misc/undefined-this-arrow-function/output.js

@@ -0,0 +1,3 @@
+"use strict";
+
+var foo = () => void 0;

packages/babel-plugin-transform-modules-commonjs/test/fixtures/misc/undefined-this-root-call/output.js

@@ -0,0 +1,3 @@
+"use strict";
+
+(void 0).foo();

packages/babel-plugin-transform-modules-commonjs/test/fixtures/misc/undefined-this-root-declaration/output.js

@@ -0,0 +1,3 @@
+"use strict";
+
+var self = void 0;

packages/babel-plugin-transform-modules-commonjs/test/fixtures/misc/undefined-this-root-reference/output.js

@@ -0,0 +1,3 @@
+"use strict";
+
+void 0;