use more specific type 'FP-Formula' instead of just 'Formula'

Author: kfriedberger

src/org/sosy_lab/java_smt/api/FloatingPointFormulaManager.java

@@ -75,7 +75,7 @@ FloatingPointFormula castFrom(
       FloatingPointType targetType,
       FloatingPointRoundingMode pFloatingPointRoundingMode);
 
-  FloatingPointFormula round(Formula formula, FloatingPointRoundingMode roundingMode);
+  FloatingPointFormula round(FloatingPointFormula formula, FloatingPointRoundingMode roundingMode);
 
   // ----------------- Arithmetic relations, return type NumeralFormula -----------------
 

src/org/sosy_lab/java_smt/basicimpl/AbstractFloatingPointFormulaManager.java

@@ -390,7 +390,7 @@ public BooleanFormula isSubnormal(FloatingPointFormula pNumber) {
   protected abstract TFormulaInfo isSubnormal(TFormulaInfo pParam);
 
   @Override
-  public FloatingPointFormula round(Formula pFormula, FloatingPointRoundingMode pRoundingMode) {
+  public FloatingPointFormula round(FloatingPointFormula pFormula, FloatingPointRoundingMode pRoundingMode) {
     return wrap(round(extractInfo(pFormula), pRoundingMode));
   }