Subzero: Add necessary PNaCl files for standalone build.
The README.txt file is new; all other files under pnacl-llvm/ are copied verbatim from the pnacl-llvm repo.
BUG= none
R=kschimpf@google.com
Review URL: https://codereview.chromium.org/1960393002 .
diff --git a/docs/README.rst b/docs/README.rst
index 0257558..922d99d 100644
--- a/docs/README.rst
+++ b/docs/README.rst
@@ -44,6 +44,27 @@
The result of the ``make`` command is the target ``pnacl-sz`` in the current
directory.
+Building within LLVM trunk
+--------------------------
+
+Subzero can also be built from within a standard LLVM trunk checkout. Here is
+an example of how it can be checked out and built::
+
+ mkdir llvm-git
+ cd llvm-git
+ git clone http://llvm.org/git/llvm.git
+ cd llvm/projects/
+ git clone https://chromium.googlesource.com/native_client/pnacl-subzero
+ cd ../..
+ mkdir build
+ cd build
+ cmake -G Ninja ../llvm/
+ ninja
+ ./bin/pnacl-sz -version
+
+This creates a default build of ``pnacl-sz``; currently any options such as
+``DEBUG=1`` or ``MINIMAL=1`` have to be added manually.
+
``pnacl-sz``
------------