[clang-scan-view] Force utf-8 when handling report (python2 only)

[serge-sans-paille]

Summary

If the report file contains unicode characters, under Python2, opening the file does not decode it to utf-8 by default.

clang/tools/scan-view/share/ScanView.py

def send_patched_file(self, path, ctype):
         # Allow a very limited set of variables. This is pretty gross.
         variables = {}
         variables['report'] = ''
         m = kReportFileRE.match(path)
         if m:
             variables['report'] = m.group(2)
 
         try:
-            f = open(path,'r')
+            f = open(path,'rb')
         except IOError:
             return self.send_404()
         fs = os.fstat(f.fileno())
-        data = f.read()
+        data = f.read().decode('utf-8')
         for a,b in kReportReplacements:
             data = a.sub(b % variables, data)
         return self.send_string(data, ctype, mtime=fs.st_mtime)
 
 
 def create_server(address, options, root):
     import Reporter
 
     reporters = Reporter.getReporters()
 
     return ScanViewServer(address, ScanViewRequestHandler,
                           root,
                           reporters,
                           options)