#298 HIGHWORD-operator returns wrong values

[qWord]

The HIGHWORD operator returns wrong values (behaves like SAR 16):

;----
foo = -1
%echo HIGH 1: @CatStr(%HIGHWORD foo)
foo = 0ffffffffh
%echo HIGH 2: @CatStr(%HIGHWORD foo)
foo = 07fffffffh
%echo HIGH 3: @CatStr(%HIGHWORD foo)
;----

jWasm output is:
HIGH 1: -1
HIGH 2: 4294967295
HIGH 3: 32767

MASM returns:
HIGH 1: 65535
HIGH 2: 65535
HIGH 3: 32767

regrads, qWord