tests: Trim .nim files trailing whitespace

via OSX: find . -name '*.nim' -exec sed -i '' -E 's/[[:space:]]+$//' {} +

tests/controlflow/tblock1.nim

@@ -3,16 +3,16 @@ discard """
   line: 14
   errormsg: "undeclared identifier: \'ha\'"
 """
-# check for forward label and
-# for failure when label is not declared
-
-proc main =
-  block endLess:
-    write(stdout, "Muaahh!\N")
-    break endLess
-
-  break ha #ERROR
-
-main()
+# check for forward label and
+# for failure when label is not declared
+
+proc main =
+  block endLess:
+    write(stdout, "Muaahh!\N")
+    break endLess
+
+  break ha #ERROR
+
+main()