fix warnings

not sure if it was intentional that this code was unused. i assume the handling of nan is done by softfloat?

Author: Rafael Stahl

src/vm/fp_functions.cpp

@@ -238,9 +238,7 @@ uint64_t fconv_f2d(uint32_t v1, uint8_t mode){
 }
 
 uint64_t fadd_d(uint64_t v1, uint64_t v2, uint8_t mode) {
-    bool nan = (v1&defaultNaNF32UI)==quiet_nan32;
-    bool snan = softfloat_isSigNaNF32UI(v1);
-   float64_t v1f{v1},v2f{v2};
+    float64_t v1f{v1},v2f{v2};
     softfloat_roundingMode=rmm_map[mode&0x7];
     softfloat_exceptionFlags=0;
     float64_t r =f64_add(v1f, v2f);