Fix asansymbolizer's demangle problem.

PROBLEM: It's passing --demangle=True to the llvm symbolizer but some
recent change made it so that is invalid.

FIX: pass --demangle or --no-demangle instead.

https://crrev.com/c/2436306 attempted to just update

tools/valgrind/asan/third_party/asan_symbolize.py

but that requires a lot of fixes to

tools/valgrind/asan/asan_symbolize.py

to work. So this is a temporary fix.

Also I had to run git cl format and it changed some stuff.

Bug: 1132789
Change-Id: I0358bfb49b1bd1370e607cf70d43a2f6a7ea11af
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2437085Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Fergal Daly <fergal@chromium.org>
Auto-Submit: Fergal Daly <fergal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#814031}

tools/valgrind/asan/third_party/asan_symbolize.py

@@ -79,12 +79,15 @@ class LLVMSymbolizer(Symbolizer):
     self.pipe = self.open_llvm_symbolizer()
 
   def open_llvm_symbolizer(self):
-    cmd = [self.symbolizer_path,
+    cmd = [
+        self.symbolizer_path,
         '--use-symbol-table=true',
-           '--demangle=%s' % demangle,
+        # TODO(https://crbug.com/1132789) remove this temporary fix.
+        '--%sdemangle' % ("" if demangle else "no-"),
         '--functions=linkage',
         '--inlining=true',
-           '--default-arch=%s' % self.default_arch]
+        '--default-arch=%s' % self.default_arch
+    ]
     if self.system == 'Darwin':
       for hint in self.dsym_hints:
         cmd.append('--dsym-hint=%s' % hint)