Comment out questions

These should be filed in issues if we consider them useful

Author: pierwill

src/overview.md

@@ -353,6 +353,7 @@ For more details on bootstrapping, see
 [_bootstrapping_]: https://en.wikipedia.org/wiki/Bootstrapping_(compilers)
 [rustc-bootstrap]: building/bootstrapping.md
 
+<!--
 # Unresolved Questions
 
 - Does LLVM ever do optimizations in debug builds?
@@ -362,7 +363,8 @@ For more details on bootstrapping, see
 - What is the main source entry point for `X`?
 - Where do phases diverge for cross-compilation to machine code across
   different platforms?
-
+-->
+  
 # References
 
 - Command line parsing