tests: Trim .nim files trailing whitespace

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

tests/varres/tvarres1.nim

@@ -7,10 +7,10 @@ discard """
 var
   g = 5
 
-proc p(): var int = 
+proc p(): var int =
   var bla: int
   result = bla
-  
+
 p() = 45
 
 echo g

tests/varres/tvarres2.nim

@@ -7,9 +7,9 @@ discard """
 var
   g = 5
 
-proc p(): var int = 
+proc p(): var int =
   result = 89
-  
+
 p() = 45
 
 echo g

tests/varres/tvarres3.nim

@@ -5,10 +5,10 @@ discard """
 var
   g = 5
 
-proc p(): var int = 
+proc p(): var int =
   var bla = addr(g) #: array [0..7, int]
   result = bla[]
-  
+
 p() = 45
 
 echo g

tests/varres/tvartup.nim

@@ -6,7 +6,7 @@ discard """
 
 proc divmod(a, b: int): tuple[di, mo: int] =
   return (a div b, a mod b)
-  
+
 var (x, y) = divmod(15, 6)
 stdout.write(x)
 stdout.write(" ")