Remove pessimation of .round($x)

Also using a literal param in MMD, which is still not optimized away.

Author: lizmat

src/core/Int.pm

@@ -69,7 +69,6 @@ my class Int does Real { # declared in BOOTSTRAP
     method ceiling(Int:D:) { self }
     proto method round(|) {*}
     multi method round(Int:D:) { self }
-    multi method round(Int:D: 1) { self }
     multi method round(Int:D: $scale as Real) { (self / $scale + 1/2).floor * $scale }
 
     method lsb(Int:D:) {

src/core/Real.pm

@@ -43,9 +43,6 @@ my role Real does Numeric {
     multi method round(Real:D:) {
         (self + 1/2).floor; # Rat NYI here, so no .5
     }
-    multi method round(Real:D: 1) {
-        (self + 1/2).floor;
-    }
     multi method round(Real:D: $scale as Real) {
         (self / $scale + 1/2).floor * $scale;
     }