Fix define-case-lambda-to-define size issue (#238)

Fixes #226.

default-recommendations/function-definition-shortcuts-test.rkt

@@ -215,6 +215,22 @@ test: "case-lambda with default arg not refactorable when required args out of o
 ------------------------------
 
 
+test: "case-lambda with default arg not refactorable when default is a multiline expression"
+------------------------------
+(define f
+  (case-lambda
+    [(a b c)
+     (f a
+        b
+        c
+        (let ([x 42])
+          (displayln x)
+          x))]
+    [(a b c x)
+     1]))
+------------------------------
+
+
 test: "case-lambda with default arg and multiple body forms"
 ------------------------------
 (define f

default-recommendations/function-definition-shortcuts.rkt

@@ -96,6 +96,7 @@
         (usage:id usage1:id ... default:expr)]
        [(case2-arg:id ... bonus-arg:id)
         body ...]))
+   #:when (oneline-syntax? #'default)
    #:when (free-identifier=? #'id #'usage)
    #:when (free-identifiers=? #'(case1-arg ...) #'(case2-arg ...))
    #:when (free-identifiers=? #'(case1-arg ...) #'(usage1 ...))