New var creation with right bit shift shows incorrect result using same initializer

The point is -IMO - there is something wrong with floating point calculation. The bit-mask mismatch is a result of the floating point error.

The result of calculation 915E6 * Math.pow(2,19) in Espruino is not 479723520000000, it's 479723519999999.9375.

To demonstrate it, ran this in

• Espruino 'Linux' build on my laptop
  
• DS-D6 (nRF52832, just sitting in a box, BLE console is really convenient :) )
  
• Browser console
  
• node v8.11.2
  
• F# interactive (.Net, to test on completely different platform)
  
  

Results are identical in non-Espruino environments:

> 915E6 * Math.pow(2,19)
// The result in Espruino: 479723519999999.9375  
// The result in browser / node / F#: 479723520000000

Oh, btw just bit-shifting indeed wraps around in browser & node:

> 915E6<<10
657129472
> 915E6<<11
1314258944
> 915E6<<12
-1666449408
> 915E6<<13
962068480
> 915E6<<14
1924136960
> 915E6<<15
-446693376
> 915E6<<16
-893386752
> 915E6<<17
-1786773504
> 915E6<<18
721420288
> 915E6<<19
1442840576