report malformed int and float patterns

compiler/reporting/src/error/canonicalize.rs

@@ -338,6 +338,28 @@ fn pretty_runtime_error<'b>(
                 ])
             }
         }
+        RuntimeError::MalformedPattern(problem, region) => {
+            use roc_parse::ast::Base;
+            use roc_problem::can::MalformedPatternProblem::*;
+
+            let name = match problem {
+                MalformedInt => "integer",
+                MalformedFloat => "float",
+                MalformedBase(Base::Hex) => "hex integer",
+                MalformedBase(Base::Binary) => "binary integer",
+                MalformedBase(Base::Octal) => "octal integer",
+            };
+
+            alloc.stack(vec![
+                alloc.concat(vec![
+                    alloc.reflow("This "),
+                    alloc.text(name),
+                    alloc.reflow(" pattern is malformed:"),
+                ]),
+                alloc.region(region),
+            ])
+        }
+
         other => {
             //    // Example: (5 = 1 + 2) is an unsupported pattern in an assignment; Int patterns aren't allowed in assignments!
             //    UnsupportedPattern(Region),