glsl: Don't use base type for bit-not when there's an error

Other parts of the compiler assume that expressions will have
well-formed types or the error type.  Just using the type of the thing
being operated on can cause expressions like ~3.14 or ~false to not
have a well-formed type.  This could then result in an assertion
failure in the context epxression handler.

If there is an error processing the expression, set the type of the IR
expression to error.

Fixes piglit's bit-not-0[789].frag tests.

NOTE: This is a candidate for the 7.11 branch.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=42755
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Cc: Vinson Lee <vlee@vmware.com>

src/glsl/ast_to_hir.cpp

@@ -1184,7 +1184,7 @@ ast_expression::hir(exec_list *instructions,
 	 error_emitted = true;
       }
 
-      type = op[0]->type;
+      type = error_emitted ? glsl_type::error_type : op[0]->type;
       result = new(ctx) ir_expression(ir_unop_bit_not, type, op[0], NULL);
       break;