Escape latex newline commands with extra vertical space (WebAssembly#1826)

Fix a sequence that Bikeshed is treating as a macro and rewriting.

This is a workaround for WebAssembly#1823

Author: dschuff

document/core/util/bikeshed_fixup.py

@@ -87,6 +87,9 @@ def Main():
                 r'\1',
                 data, flags=re.DOTALL)
 
+  # Escape some latex sequences that Bikeshed interprets as macros
+  data = data.replace(r' \\[1ex]', r' \\\[1ex]')
+
   sys.stdout.write(data)
 
 Main()