Fix function name computation for literal values (#7435)

* Fix name computation for literal values

* Add more computed literal test cases

* Always return a string in getNameFromLiteralId

- Also concatenate quasis id for regex literal

* Add a test clarifying function name for template literals

* Remove useless else ifs

packages/babel-plugin-transform-function-name/test/fixtures/issues/7199/input.js

@@ -0,0 +1,8 @@
+const x = {
+  [null]: function () {},
+  [/regex/gi]: function () {},
+  [`y`]: function () {},
+  [`abc${y}def`]: function () {},
+  [0]: function () {},
+  [false]: function () {},
+};

packages/babel-plugin-transform-function-name/test/fixtures/issues/7199/options.json

@@ -0,0 +1,3 @@
+{
+  "plugins": ["external-helpers", "transform-function-name"]
+}

packages/babel-plugin-transform-function-name/test/fixtures/issues/7199/output.js

@@ -0,0 +1,8 @@
+const x = {
+  [null]: function _null() {},
+  [/regex/gi]: function _regex_gi() {},
+  [`y`]: function y() {},
+  [`abc${y}def`]: function abcdef() {},
+  [0]: function _() {},
+  [false]: function _false() {}
+};