Fix a test case failure in spf grades.
library/math.m:
Document how the "next integer" operations handle arguments of infinite
magnitude.
tests/general/float_test.m:
s/ceil/ceiling/ in a spot.
Test next integer operations with +/-infinity (and zero).
In the erlang grades, avoid running parts of these tests that
rely on library functionality that is NYI.
Document what the expected outputs correspond to.
tests/general/float_test.exp:
Update this expected output.
tests/general/float_test.exp2:
Replace the contents of this file: previously it contained output for
some ancient version of MSVC; it now contains the spf version of the
output.
tests/general/float_test.exp3:
A new expected output for the erlang grades.
Estimated hours taken: 0.25
Adapt the tests in the general directory so that the version of the
Mercury compiler built with MSVC passes them in the hlc.gc grade.
float_test.exp2:
string_format_test.exp3:
The MSVC runtime prints out floating points using three digits for
the exponent.
