Improve StrictMath support (#10186)

Fixes #9754

Adds all missing methods as simple aliases to the respective `Math`
methods, consistent with the rest of the class.

Fixes a discrepancy in the return type of `Math.floorMod(long, int)`.

Author: zbynek

user/super/com/google/gwt/emul/java/lang/Math.java

@@ -150,8 +150,8 @@ public static long floorMod(long dividend, long divisor) {
     return ((dividend % divisor) + divisor) % divisor;
   }
 
-  public static long floorMod(long dividend, int divisor) {
-    return floorMod(dividend, (long) divisor);
+  public static int floorMod(long dividend, int divisor) {
+    return (int) floorMod(dividend, (long) divisor);
   }
 
   @SuppressWarnings("CheckStyle.MethodName")

user/super/com/google/gwt/emul/java/lang/StrictMath.java

@@ -54,7 +54,7 @@ public static double atan(double x) {
   }
 
   public static double atan2(double y, double x) {
-    return Math.atan(x);
+    return Math.atan2(y, x);
   }
 
   public static double ceil(double x) {
@@ -236,4 +236,105 @@ public static int toIntExact(long x) {
   public static double toRadians(double x) {
     return Math.toRadians(x);
   }
+
+  public static long abs(long x) {
+    return Math.abs(x);
+  }
+
+  public static int decrementExact(int x) {
+    return Math.decrementExact(x);
+  }
+
+  public static long decrementExact(long x) {
+    return Math.decrementExact(x);
+  }
+
+  public static int incrementExact(int x) {
+    return Math.incrementExact(x);
+  }
+
+  public static long incrementExact(long x) {
+    return Math.incrementExact(x);
+  }
+
+  public static long multiplyExact(long x, int y) {
+    return Math.multiplyExact(x, y);
+  }
+
+  public static long negateExact(long x) {
+    return Math.negateExact(x);
+  }
+
+  public static int negateExact(int x) {
+    return Math.negateExact(x);
+  }
+
+  public static int getExponent(float x) {
+    return Math.getExponent(x);
+  }
+
+  public static int getExponent(double x) {
+    return Math.getExponent(x);
+  }
+
+  public static int floorMod(long x, int y) {
+    return Math.floorMod(x, y);
+  }
+
+  public static double cbrt(double x) {
+    return Math.cbrt(x);
+  }
+
+  @SuppressWarnings("CheckStyle.MethodName")
+  public static double IEEEremainder(double x, double y) {
+    return Math.IEEEremainder(x, y);
+  }
+
+  public static long floorDiv(long x, int y) {
+    return Math.floorDiv(x, y);
+  }
+
+  public static long multiplyFull(int x, int y) {
+    return Math.multiplyFull(x, y);
+  }
+
+  public static int absExact(int x) {
+    return Math.absExact(x);
+  }
+
+  public static long absExact(long x) {
+    return Math.absExact(x);
+  }
+
+  public static double ulp(double x) {
+    return Math.ulp(x);
+  }
+
+  public static float ulp(float x) {
+    return Math.ulp(x);
+  }
+
+  public static double nextAfter(double x, double direction) {
+    return Math.nextAfter(x, direction);
+  }
+
+  public static float nextAfter(float x, double direction) {
+    return Math.nextAfter(x, direction);
+  }
+
+  public static double nextUp(double x) {
+    return Math.nextUp(x);
+  }
+
+  public static float nextUp(float x) {
+    return Math.nextUp(x);
+  }
+
+  public static double nextDown(double x) {
+    return Math.nextDown(x);
+  }
+
+  public static float nextDown(float x) {
+    return Math.nextDown(x);
+  }
 }

user/test/com/google/gwt/emultest/java8/lang/MathTest.java

@@ -162,10 +162,10 @@ public void testFloorModLongs() {
   }
 
   public void testFloorModLongInt() {
-    assertEquals(0L, Math.floorMod(0L, 1L));
-    assertEquals(1L, Math.floorMod(4L, 3L));
-    assertEquals(0L, Math.floorMod(Long.MIN_VALUE, Integer.MIN_VALUE));
-    assertEquals(1L, Math.floorMod(Long.MAX_VALUE, Integer.MAX_VALUE));
+    assertEquals(0, Math.floorMod(0L, 1L));
+    assertEquals(1, Math.floorMod(4L, 3L));
+    assertEquals(0, Math.floorMod(Long.MIN_VALUE, Integer.MIN_VALUE));
+    assertEquals(1, Math.floorMod(Long.MAX_VALUE, Integer.MAX_VALUE));
     assertThrowsArithmetic(() -> Math.floorMod(1L, 0));
   }