This patch forces postgres95 to assume any floating-point value is a
float8.  It removes the requirement that you cast all floating-point
constants to float8.

We can remove alot of casts in the regression test after we are sure
this works.

If I have missed anything, would someone let me know.  I have tested
inserts of floating-point values into float8 fields, and it worked well.
Casting the number to float4 showed the same precision loss as previous
uncast values showed.

Submitted by: Bruce Momjian <maillist@candle.pha.pa.us>