We now store 32-bit integers as 32-bit integers directly which avoids
having to convert them from doubles when they're only used as 32-bit
integers anyway. :^)
This patch feels a bit incomplete and there's a lot of opportunities
to take advantage of this information. We'll have to find and exploit
them eventually.
For various statements the spec states:
Return NormalCompletion(empty).
In those cases we have been returning undefined so far, which is
incorrect.
In other cases it states:
Return Completion(UpdateEmpty(stmtCompletion, undefined)).
Which essentially means a statement is evaluated and its completion
value returned if non-empty, and undefined otherwise.
While not actually noticeable in normal scripts as the VM's "last value"
can't be accessed from JS code directly (with the exception of eval(),
see below), it provided an inconsistent experience in the REPL:
> if (true) 42;
42
> if (true) { 42; }
undefined
This also fixes the case where eval() would return undefined if the last
executed statement is not a value-producing one:
eval("1;;;;;")
eval("1;{}")
eval("1;var a;")
As a consequence of the changes outlined above, these now all correctly
return 1.
See https://tc39.es/ecma262/#sec-block-runtime-semantics-evaluation,
"NOTE 2".
Fixes#3609.
(...and ASSERT_NOT_REACHED => VERIFY_NOT_REACHED)
Since all of these checks are done in release builds as well,
let's rename them to VERIFY to prevent confusion, as everyone is
used to assertions being compiled out in release.
We can introduce a new ASSERT macro that is specifically for debug
checks, but I'm doing this wholesale conversion first since we've
accumulated thousands of these already, and it's not immediately
obvious which ones are suitable for ASSERT.
