Add raw address of expressions to the AST and HIR

src/librustc_error_codes/error_codes.rs

@@ -409,6 +409,7 @@
 E0742: include_str!("./error_codes/E0742.md"),
 E0743: include_str!("./error_codes/E0743.md"),
 E0744: include_str!("./error_codes/E0744.md"),
+E0745: include_str!("./error_codes/E0745.md"),
 ;
 //  E0006, // merged with E0005
 //  E0008, // cannot bind by-move into a pattern guard

src/librustc_error_codes/error_codes/E0745.md

@@ -0,0 +1,20 @@
+Cannot take address of temporary value.
+
+Erroneous code example:
+
+```compile_fail,E0745
+# #![feature(raw_ref_op)]
+fn temp_address() {
+    let ptr = &raw const 2;   // ERROR
+}
+```
+
+To avoid the error, first bind the temporary to a named local variable.
+
+```ignore
+# #![feature(raw_ref_op)]
+fn temp_address() {
+    let val = 2;
+    let ptr = &raw const val;
+}
+```