Style Selectors on Nonexistent Function Names

[Yiliang Liang]

Describe the bug

When Style selectors refer to non-existent function names (example), the compiler inelegantly throws an error in console.

Error message:

Uncaught (in promise) Error: Style internal error: expected 'hello' to be either a constructor or function, but was not found
    at eV (index-31a2d046.js:265:25080)
    at c9t (index-31a2d046.js:265:22888)
    at index-31a2d046.js:265:23436
    at Kr (index-31a2d046.js:190:319765)
    at ER (index-31a2d046.js:192:10471)
    at Function.rrt [as flatMap] (index-31a2d046.js:192:9809)
    at kPe (index-31a2d046.js:265:23423)
    at h9t (index-31a2d046.js:265:24016)
    at f9t (index-31a2d046.js:265:24320)
    at D9t (index-31a2d046.js:265:34718)