Consistent public constructors in ast package

Issue: SPR-14181

spring-expression/src/main/java/org/springframework/expression/spel/ast/BooleanLiteral.java

 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.expression.spel.ast;
 
 import org.springframework.asm.MethodVisitor;
@@ -20,7 +21,7 @@ import org.springframework.expression.spel.CodeFlow;
 import org.springframework.expression.spel.support.BooleanTypedValue;
 
 /**
- * Represents the literal values TRUE and FALSE.
+ * Represents the literal values {@code TRUE} and {@code FALSE}.
  *
  * @author Andy Clement
  * @since 3.0

spring-expression/src/main/java/org/springframework/expression/spel/ast/FloatLiteral.java

 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -31,7 +31,8 @@ public class FloatLiteral extends Literal {
 
 	private final TypedValue value;
 
-	FloatLiteral(String payload, int pos, float value) {
+
+	public FloatLiteral(String payload, int pos, float value) {
 		super(payload, pos);
 		this.value = new TypedValue(value);
 		this.exitTypeDescriptor = "F";
@@ -53,4 +54,5 @@ public class FloatLiteral extends Literal {
 		mv.visitLdcInsn(this.value.getValue());
 		cf.pushDescriptor(this.exitTypeDescriptor);
 	}
+
 }

spring-expression/src/main/java/org/springframework/expression/spel/ast/IntLiteral.java

 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.expression.spel.ast;
 
 import org.springframework.asm.MethodVisitor;
@@ -29,7 +30,8 @@ public class IntLiteral extends Literal {
 
 	private final TypedValue value;
 
-	IntLiteral(String payload, int pos, int value) {
+
+	public IntLiteral(String payload, int pos, int value) {
 		super(payload, pos);
 		this.value = new TypedValue(value);
 		this.exitTypeDescriptor = "I";

spring-expression/src/main/java/org/springframework/expression/spel/ast/LongLiteral.java

 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -31,12 +31,13 @@ public class LongLiteral extends Literal {
 	private final TypedValue value;
 
 
-	LongLiteral(String payload, int pos, long value) {
+	public LongLiteral(String payload, int pos, long value) {
 		super(payload, pos);
 		this.value = new TypedValue(value);
 		this.exitTypeDescriptor = "J";
 	}
 
+
 	@Override
 	public TypedValue getLiteralValue() {
 		return this.value;