based on the expr_loop_body expression and not the inner closure

Also add comments reminding that IEEE 754 requires unusual semantics for
comparison operators as applied to NaNs (x != x, if x = NaN), in case someone
in the future wants to get clever.

improvements to option module

Inlining methods/functions in core.

doc: Fix spelling error in macro tutorial

Also inlining some functions which take functions as arguments.

Adds priv qualifiers where they have been commented out before implementation.

Allow logical negation operator (!) to be overloaded

libsyntax: Fix name generation in condition! macro

support clang 3.2

This begins executing Rust code in a fresh context with no runtime environment

Updates #4386.

This is very helpful for SDL, as SDL wants you to define a function named
`SDL_main`.

...of course, it shouldn't be segfaulting, but this fixes the
build.

rs=breakage