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: 6bcd2af086 ("nir/algebraic: Add some optimizations for D3D-style Booleans")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=109075

src/compiler/nir/nir_algebraic.py

@@ -252,6 +252,14 @@ class Variable(Value):
       assert m and m.group('name') is not None
 
       self.var_name = m.group('name')
+
+      # Prevent common cases where someone puts quotes around a literal
+      # constant.  If we want to support names that have numeric or
+      # punctuation characters, we can me the first assertion more flexible.
+      assert self.var_name.isalpha()
+      assert self.var_name is not 'True'
+      assert self.var_name is not 'False'
+
       self.is_constant = m.group('const') is not None
       self.cond = m.group('cond')
       self.required_type = m.group('type')