The default float type is not very useful but for the most basic applications.
For instance, as it is now, using the math package requires conversions for float
variables (the arguments for math functions are usually float64). Typical real
applications tend to specify the floating point precision required.

This proposal removes the predeclared types float and complex. Variable declarations
without type specification but with constant floating point or complex initializer
expressions will assume the type float64 or complex128 respectively.

The predeclared function cmplx is renamed to complex.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/3423041