It can be unexpected that printing a float32 involves 64-bit floating
point routines, see for example:
https://github.com/tinygo-org/tinygo/issues/1415
This commit adds a dedicated printfloat32 instead just for printing
float32 values. It comes with a possible code size increase, but only if
both float32 and float64 values are printed. Therefore, this should be
an improvement in almost all cases.
I also tried using printfloat32 for everything (and casting a float64 to
float32 to print) but the printed values are slightly different,
breaking the testdata/math.go test for example.
