The JavaScript implementation of isDimDefined contains a check to ensure
that the dimension value is positive; the C and Java versions did not
have this check. As a result, a negative style value for 'width' (such
as that used by the "should layout node with negative width" test) would
have different layout under the C/Java implementation to the JavaScript
implementation.
This was hidden because the C/Java transpilers filtered out any negative
instantiation values from the test suite. In effect, the negative value
tests weren't running on the C/Java implementation.
This patch removes the negative value filter from the transpiler, and
makes the isDimDefined definition consistent between the three
implementations.
