test: fix common.mustCall

Don't run the 'has function been called?' checks if the test is exiting
with an error because a failed check will mask the real exception.

v0.8 doesn't have the _fatalException machinery in src/node.js and
src/node.cc so it doesn't have this issue.
node: don't malloc in FromConstructorTemplate

* allocate space for argv on the stack
* move the declaration to node_internals.h
typed arrays: make call-as-function work for ctors

Turn call-as-function calls into constructor calls. Makes the following
snippet work:

  var buf = ArrayBuffer(32);  // no 'new' but does the right thing