configure: Accept llvm-3.2

Previously the build system only checked for llvm-3.1 - 2.8.
Now also 3.2 and 3.2svn is accepted.

Signed-off-by: Fabian Deutsch <fabian.deutsch@gmx.de>
auto merge of #5561 : fabiand/rust/wllvm32, r=catamorphism

Previously the build system only checked for llvm-3.1 - 2.8.
Now also 3.2 and 3.2svn is accepted.

Signed-off-by: Fabian Deutsch <fabian.deutsch@gmx.de>
core: Inline mallocing wrapper functions

As far as I can tell, this doesn't make rust compile any
faster, but it does at least remove one level of indirection
on malloc, which might help speed up some operations.
std: change Decoder::read_option to return a generic type

This allows read_option to be used with a custom option type instead
of just core::Option.