certain symbols with print names like floats cause printer error

[JohnCarroll]

Simple test case, in 1.7-r14925M (DarwinX8664):

(print '|40s40|)

Error: FLOATING-POINT-OVERFLOW detected performing SCALE on (0 363797880709171295166015625000 40) While executing: CCL::FLOAT-AND-SCALE-AND-ROUND, in process listener(1).

The error comes from %parse-number-token, which tries too hard to actually create a float which could have the same printed representation as the symbol print name.

[JohnCarroll]

A couple of further, related test cases which also show this defect:

(print '|1000000000000000000000000000000000000000.0|)

(print '|300/000|)

[gb]

(In [15023]) WRITE-PNAME: if the call to %PARSE-NUMBER-TOKEN signals an ARITHMETIC-ERROR, treat it as if it succeeded (e.g., the pname has number syntax/would be read as a potential number, even if it's not representable.)

Fixes ticket:889 in the trunk.