V8 ran into an issue where the YAML parser our test setup is using
didn't understand the newline, and failed to parser the negative
test expectation below, causing the test to fail. This patch fixes
the issue.

- Add missing 'negative: ReferenceError' in S7.9_A5.7_T1
- Remove stale 'negative: ReferenceError' in block-local-closure-get-before-initialization
- Remove all tail-call expressions in test/built-ins/Function
- And update code in test/built-ins/Function to simply use 'f()' instead of 'var r = f(); return r'

Fixes #383

The `negative` frontmatter tag expresses an expectation for the behavior
of the test file as a whole. The `assert.throws` helper function offers
more fine-grained control over expectations because it may be applied to
specific statements and expressions. This makes it preferable in cases
where it may be used (i.e. when the test body does not describe a syntax
error or early error).

Re-implement assertions for errors to use the `assert.throws` helper
function wherever possible.