Convert old python3 cgi method into the new html one

[sylvestre.ledru]

Summary

Patch by Gianfranco Costamagna

[serge-sans-paille]

Help on function escape in cgi:

cgi.escape = escape(s, quote=None)
    Deprecated API.

I'm fine with the patch.

llvm/tools/opt-viewer/opt-viewer.py

 #!/usr/bin/env python
 
 from __future__ import print_function
 
 import argparse
-import cgi
 import errno
 import functools
+import html
 import io
 from multiprocessing import cpu_count
 import os.path
 import re
 import shutil
 import sys
 
 from pygments import highlight

 
 class IndexRenderer:
     def __init__(self, output_dir, should_display_hotness, max_hottest_remarks_on_index):
         self.stream = io.open(os.path.join(output_dir, 'index.html'), 'w', encoding='utf-8')
         self.should_display_hotness = should_display_hotness
         self.max_hottest_remarks_on_index = max_hottest_remarks_on_index
 
     def render_entry(self, r, odd):
-        escaped_name = cgi.escape(r.DemangledFunctionName)
+        escaped_name = html.escape(r.DemangledFunctionName)
         print(u'''
 <tr>
 <td class=\"column-entry-{odd}\"><a href={r.Link}>{r.DebugLocString}</a></td>
 <td class=\"column-entry-{odd}\">{r.RelativeHotness}</td>
 <td class=\"column-entry-{odd}\">{escaped_name}</td>
 <td class=\"column-entry-{r.color}\">{r.PassWithDiffPrefix}</td>
 </tr>'''.format(**locals()), file=self.stream)
 

llvm/tools/opt-viewer/optrecord.py

 #!/usr/bin/env python
 
 from __future__ import print_function
 
 import io
 import yaml
 # Try to use the C parser.
 try:
     from yaml import CLoader as Loader
 except ImportError:
     print("For faster parsing, you may want to install libYAML for PyYAML")
     from yaml import Loader
 
-import cgi
+import html
 from collections import defaultdict
 import fnmatch
 import functools
 from multiprocessing import Lock
 import os, os.path
 import subprocess
 try:
     # The previously builtin function `intern()` was moved
def getArgString(self, mapping):
         dl = mapping.get('DebugLoc')
         if dl:
             del mapping['DebugLoc']
 
         assert(len(mapping) == 1)
         (key, value) = list(mapping.items())[0]
 
         if key == 'Caller' or key == 'Callee' or key == 'DirectCallee':
-            value = cgi.escape(self.demangle(value))
+            value = html.escape(self.demangle(value))
 
         if dl and key != 'Caller':
             dl_dict = dict(list(dl))
             return u"<a href={}>{}</a>".format(
                 make_link(dl_dict['File'], dl_dict['Line']), value)
         else:
             return value