NegativeArraySizeException when running MR jobs with large data size

We are using bit shifting to double the byte array in IFile's nextRawValue method to store the byte values in it. With large dataset it can easily happen that we shift the leftmost bit when we are calculating the size of the array, which can lead to a negative number as the array size, causing the NegativeArraySizeException.

It would be safer to expand the backing array with a 1.5x factor, and have a check not to extend Integer's max value during that.