[generation] Avoid generating trailing whitespace

tools/generation/lib/template.py

@@ -20,7 +20,11 @@ def indent(text, prefix = '    '):
     else:
         lines = text.split('\n')
 
-    return prefix + ('\n' + prefix).join(lines)
+    indented = map(
+        lambda line: line if len(line) == 0 else prefix + line,
+        lines)
+
+    return '\n'.join(indented)
 
 class Template:
     def __init__(self, filename):

tools/generation/test/expected/normal/info-multiline-folding-normal.js

+// This file was procedurally generated from the following sources:
+// - tools/generation/test/fixtures/normal.case
+// - tools/generation/test/fixtures/normal/info-multiline-folding.template
+/*---
+description: foobar (First template name)
+es6id: 1.2.3
+flags: [generated, a, b]
+includes: [foo.js]
+info: >
+    This is an "info" field with an
+
+    empty line
+    Trailing white space in the template: 
+    should be preserved:	
+     
+      
+       
+        
+    	
+    		
+    	 	  
+
+    case info
+---*/
+
+// Trailing white space in the test body: 
+// should be preserved:	
+ 
+  
+   
+    
+	
+		
+	 	  
+
+'This is "teardown" code.';

tools/generation/test/fixtures/normal/info-multiline-folding.template

+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+name: First template name
+path: normal/info-multiline-folding-
+es6id: 1.2.3
+info: |
+    This is an "info" field with an
+
+    empty line
+    Trailing white space in the template: 
+    should be preserved:	
+     
+      
+       
+        
+    	
+    		
+    	 	  
+---*/
+
+// Trailing white space in the test body: 
+// should be preserved:	
+ 
+  
+   
+    
+	
+		
+