Path expressions

**Syntax **
PathExpression :
   | QualifiedPathInExpression

A path used as an expression context denotes either a local variable or an item. Path expressions that resolve to local or static variables are place expressions, other paths are value expressions. Using a static mut variable requires an unsafe block.

fn main() {
mod globals {
    pub static STATIC_VAR: i32 = 5;
    pub static mut STATIC_MUT_VAR: i32 = 7;
let local_var = 3;
unsafe { globals::STATIC_MUT_VAR };
let some_constructor = Some::<i32>;
let push_integer = Vec::<i32>::push;
let slice_reverse = <[i32]>::reverse;