Allow patch files to add top-level declarations to the patched library.

corelib/unified/math/base.dart

Index: corelib/unified/math/base.dart
diff --git a/corelib/unified/math/base.dart b/corelib/unified/math/base.dart
index 75696e842aafc879eb264a9c3482842a095bd88a..1c358c87378c71b36e4f08eee092e850cf30900b 100644
--- a/corelib/unified/math/base.dart
+++ b/corelib/unified/math/base.dart
@@ -58,21 +58,76 @@ external int parseInt(String str);
  */
 external double parseDouble(String str);
 
+/**
+  * Returns the minimum of two numbers. If either argument is NaN returns NaN.
+  * The minimum of [:-0.0:] and [:0.0:] is [:-0.0:]. If both arguments are
+  * equal (int and doubles with the same mathematical value are equal) then
+  * it is unspecified which of the two arguments is returned.
+  */
 num min(num a, num b) {
-  int c = a.compareTo(b);
-  if (c == 0) return a;
-  if (c < 0) {
-    if ((b is double) && b.isNaN()) return b;
-    return a;
+  if (a is num) {
+    // TODO(floitsch): merge this if into the previous one, once dart2js
+    // correctly propagates types for logical ands.
+    if (b is num) {
+      if (a > b) return b;
+      if (a < b) return a;
+      if (b is double) {
+        // Special case for NaN and -0.0. If one argument is NaN return NaN.
+        // [min] must also distinguish between -0.0 and 0.0.
+        if (a is double) {
+          if (a == 0.0) {
+            // a is either 0.0 or -0.0. b is either 0.0, -0.0 or NaN.
+            // The following returns -0.0 if either a or b is -0.0, and it
+            // returns NaN if b is NaN.
+            return (a + b) * a * b;
+          }
+        }
+        // Check for NaN and b == -0.0.
+        if (a == 0 && b.isNegative() || b.isNaN()) return b;
+        return a;
+      }
+      return a;
+    }
+    throw new IllegalArgumentException(b);
   }
-  if ((a is double) && a.isNaN()) return a;
-  return b;
+  throw new IllegalArgumentException(a);
 }
 
+/**
+  * Returns the maximum of two numbers. If either argument is NaN returns NaN.
+  * The maximum of [:-0.0:] and [:0.0:] is [:0.0:]. If both arguments are
+  * equal (int and doubles with the same mathematical value are equal) then
+  * it is unspecified which of the two arguments is returned.
+  */
 num max(num a, num b) {
-  // NaNs are handled correctly since the compareTo function always considers
-  // them to be bigger than any other operand.
-  return (a.compareTo(b) < 0) ? b : a;
+  if (a is num) {
+    // TODO(floitsch): merge this if into the previous one, once dart2js
+    // correctly propagates types for logical ands.
+    if (b is num) {
+      if (a > b) return a;
+      if (a < b) return b;
+      if (b is double) {
+        // Special case for NaN and -0.0. If one argument is NaN return NaN.
+        // [max] must also distinguish between -0.0 and 0.0.
+        if (a is double) {
+          if (a == 0.0) {
+            // a is either 0.0 or -0.0. b is either 0.0, -0.0, or NaN.
+            // The following returns 0.0 if either a or b is 0.0, and it
+            // returns NaN if b is NaN.
+            return a + b;
+          }
+        }
+        // Check for NaN.
+        if (b.isNaN()) return b;
+        return a;
+      }
+      // max(-0.0, 0) must return 0.
+      if (b == 0 && a.isNegative()) return b;
+      return a;
+    }
+    throw new IllegalArgumentException(b);
+  }
+  throw new IllegalArgumentException(a);
 }
 
 /**