Linux: add option to use system tcmalloc (off by default)

tools/generate_shim_headers/generate_shim_headers.py

Index: tools/generate_shim_headers/generate_shim_headers.py
diff --git a/tools/generate_shim_headers/generate_shim_headers.py b/tools/generate_shim_headers/generate_shim_headers.py
index 891b75c2debc3a31d242bfae6f07e9d899d72703..81c531b2e6a0d55c5efa436954dfc016aa7b2eb6 100755
--- a/tools/generate_shim_headers/generate_shim_headers.py
+++ b/tools/generate_shim_headers/generate_shim_headers.py
@@ -29,6 +29,7 @@ def GeneratorMain(argv):
   parser.add_option('--headers-root', action='append')
   parser.add_option('--define', action='append')
   parser.add_option('--output-directory')
+  parser.add_option('--prefix', default='')
   parser.add_option('--use-include-next', action='store_true')
   parser.add_option('--outputs', action='store_true')
   parser.add_option('--generate', action='store_true')
@@ -80,10 +81,11 @@ def GeneratorMain(argv):
             for header in include_before.split(':'):
               f.write('#include %s\n' % header)
 
+          include_target = options.prefix + header_filename
           if options.use_include_next:
-            f.write('#include_next <%s>\n' % header_filename)
+            f.write('#include_next <%s>\n' % include_target)
           else:
-            f.write('#include <%s>\n' % header_filename)
+            f.write('#include <%s>\n' % include_target)
 
           if include_after:
             for header in include_after.split(':'):