Add wording about conversion rank changes (#222)

This updates wording in the "Problems with this solution" section to
reflect the confirmed problems caused by integer literals and the
speculative problems relating to floating point precision and conversion
ranks.

proposals/0017-conforming-literals.md

@@ -80,11 +80,17 @@ overloads.
 
 ### Problems with this solution
 
-This is a significant change in behavior which will cause subtle issues for
-existing shaders due to variations in precision of compile-time constant
-evaluation. This behavior difference will cause subtle bugs that will be
-challenging to diagnose in the midst of a larger compiler transition (i.e.
-adopting Clang).
+This is a significant change in behavior which will cause issues for existing
+shaders. We have observed rendering defects caused by the difference in
+classifying types for integer literals (more details below). We have also
+speculated that issues could arise for two further reasons: (1) variations in
+precision of compile-time constant evaluation, and (2) the change in conversion
+rank for un-suffixed literals (`literal float` was the lowest rank `float` ranks
+above smaller types).
+
+In the observed case and the two hypothetical cases, this behavior difference
+will cause bugs that will be challenging to diagnose in the midst of a larger
+compiler transition (i.e. adopting Clang).
 
 For that reason, this feature proposal targets HLSL 202x, with support for the
 new literal behavior in DXC.