nir/algebraic: Don't put quotes around floating point literals

nir/algebraic: Don't put quotes around floating point literals

The quotation marks around 1.0 cause it to be treated as a string
instead of a floating point value.  The generator then treats it as an
arbitrary variable replacement, so any iand involving a ('ineg', ('b2i',
a)) matches.

v2: Remove misleading comment about sized literals (suggested by
Timothy).  Add assertion that the name of a varible is entierly
alphabetic (suggested by Jason).

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Tested-by: Timothy Arceri <tarceri@itsqueeze.com> [v1]
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com> [v1]
Fixes: 6bcd2af0863 ("nir/algebraic: Add some optimizations for D3D-style Booleans")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=109075