generate double hashCode: simplify expr (IDEA-103687)

(cherry picked from commit 8796e6596a3e3e142b072d405bbf37071b810c5c)

java/java-impl/src/com/intellij/codeInsight/generation/GenerateEqualsHelper.java

@@ -407,10 +407,9 @@ public class GenerateEqualsHelper implements Runnable {
 
   private static void addTempForDoubleInitialization(PsiField field, @NonNls StringBuilder buffer) {
     buffer.append(" = ");
+    buffer.append("Double.doubleToLongBits(");
     buffer.append(field.getName());
-    buffer.append(" != +0.0d ? Double.doubleToLongBits(");
-    buffer.append(field.getName());
-    buffer.append(") : 0L;\n");
+    buffer.append(");\n");
   }
 
   private String addTempDeclaration(@NonNls StringBuilder buffer, boolean resultDeclarationCompleted) {

java/java-tests/testData/codeInsight/generateEquals/afterHashCode.java

@@ -24,7 +24,7 @@ class Test {
         result = i;
         result = 31 * result + a.hashCode();
         result = 31 * result + (b != null ? b.hashCode() : 0);
-        temp = c != +0.0d ? Double.doubleToLongBits(c) : 0L;
+        temp = Double.doubleToLongBits(c);
         result = 31 * result + (int) (temp ^ (temp >>> 32));
         return result;
     }

java/java-tests/testData/codeInsight/generateEquals/afterOneDoubleField.java

@@ -13,7 +13,7 @@ class Test {
     }
 
     public int hashCode() {
-        final long temp = d != +0.0d ? Double.doubleToLongBits(d) : 0L;
+        final long temp = Double.doubleToLongBits(d);
         return (int) (temp ^ (temp >>> 32));
     }
 }