Further support for floating-point. Literals with exponents work

and literals with the 'f32' or 'f64' suffixes work as well. In
addition, logging things with the f32 or f64 type works. (float is
still assumed to be a synonym for f64).

src/comp/front/parser.rs

@@ -545,6 +545,10 @@ impure fn parse_lit(parser p) -> ast.lit {
             p.bump();
             lit = ast.lit_mach_int(tm, i);
         }
+        case (token.LIT_MACH_FLOAT(?tm, ?s)) {
+            p.bump();
+            lit = ast.lit_mach_float(tm, s);
+        }
         case (token.LIT_CHAR(?c)) {
             p.bump();
             lit = ast.lit_char(c);