tests: Trim .nim files trailing whitespace

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

tests/varstmt/tlet.nim

@@ -11,7 +11,7 @@ proc main =
     echo("Very funny, your name is name.")
   else:
     echo("Hi, ", name, "!")
-    
+
   let (x, y) = ("abc", name)
   echo y, x
 

tests/varstmt/tvardecl.nim

@@ -2,14 +2,14 @@ discard """
   file: "tvardecl.nim"
   output: "44"
 """
-# Test the new variable declaration syntax
-
-var
-  x = 0
-  s = "Hallo"
-  a, b: int = 4
-
-write(stdout, a)
-write(stdout, b) #OUT 44
+# Test the new variable declaration syntax
+
+var
+  x = 0
+  s = "Hallo"
+  a, b: int = 4
+
+write(stdout, a)
+write(stdout, b) #OUT 44