Use the more efficient arity check for Hash#{each_pair,map}

* Since it does not seem to affect semantics at all, since anyway a
  non-lambda Proc will destructure a single Array argument, unless
  there is a rest argument (but then arity would be negative) or
  there is no rest argument, no optional argument and required <= 1
  (but then required > 1 for yieldPair() is always false).

Author: eregon

src/main/java/org/truffleruby/core/hash/HashNodes.java

@@ -501,7 +501,8 @@ protected RubyHash eachBuckets(RubyHash hash, RubyProc block) {
 
         private Object yieldPair(RubyProc block, Object key, Object value) {
             // MRI behavior, see rb_hash_each_pair()
-            if (arityMoreThanOne.profile(block.getArityNumber() > 1)) {
+            // We use getMethodArityNumber() here since for non-lambda the semantics are the same for both branches
+            if (arityMoreThanOne.profile(block.sharedMethodInfo.getArity().getMethodArityNumber() > 1)) {
                 return yield(block, key, value);
             } else {
                 return yield(block, createArray(new Object[]{ key, value }));
@@ -722,7 +723,8 @@ protected RubyArray mapBuckets(RubyHash hash, RubyProc block,
 
         private Object yieldPair(RubyProc block, Object key, Object value) {
             // MRI behavior, see rb_hash_each_pair()
-            if (arityMoreThanOne.profile(block.getArityNumber() > 1)) {
+            // We use getMethodArityNumber() here since for non-lambda the semantics are the same for both branches
+            if (arityMoreThanOne.profile(block.sharedMethodInfo.getArity().getMethodArityNumber() > 1)) {
                 return yield(block, key, value);
             } else {
                 return yield(block, createArray(new Object[]{ key, value }));