Fix ConstantDynamic to use the right tag.

The class ConstantDynamic was incorrectly using the `InvokeDynamic` tag
during construction which meant after reading in code containing a
`Dynamic` reference, it would incorrectly be written out as an
`InvokeDynamic` reference. There is not much code out there using
Dynamic so wasn't uncovered before.

Fixes #68

bcel-builder/src/main/java/org/aspectj/apache/bcel/classfile/ConstantDynamic.java

 	}
 
 	public ConstantDynamic(int readUnsignedShort, int nameAndTypeIndex) {
-		super(Constants.CONSTANT_InvokeDynamic);
+		super(Constants.CONSTANT_Dynamic);
 		this.bootstrapMethodAttrIndex = readUnsignedShort;
 		this.nameAndTypeIndex = nameAndTypeIndex;
 	}