[clang/docs/LibASTMatchersTutorial.rst,clang/docs/HowToSetupToolingForLLVM.rst] ninja now uses `configure.py` rather than `bootstrap.py`

[SamuelMarks]

Summary

Alternatively you can do:

cmake -Bbuild-cmake -H.
cmake --build build-cmake

Which makes ./build-cmake/ninja.

[jdoerfert]

LG, use [Docs] as tag for the commit, it should not be verbose but helpful to determine if a commit is interesting.

clang/docs/HowToSetupToolingForLLVM.rst

 
   $ git clone git://github.com/martine/ninja.git
   $ cd ninja/
-  $ ./bootstrap.py
+  $ ./configure.py --bootstrap
 
 This will result in a single binary ``ninja`` in the current directory.
 It doesn't require installation and can just be copied to any location

clang/docs/LibASTMatchersTutorial.rst

       git clone https://github.com/martine/ninja.git
       cd ninja
       git checkout release
-      ./bootstrap.py
+      ./configure.py --bootstrap
       sudo cp ninja /usr/bin/
 
       cd ~/clang-llvm