[Orc] Add a Kaleidoscope/Orc tutorial demonstrating lazy-codegen.

This tutorial builds on the initial kaleidoscope/orc tutorial by adding a
LazyEmittingLayer to the custom stack. This extra layer defers compilation
of modules in the JIT until they are statically referenced.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228459 91177308-0d34-0410-b5e6-96231b3b80d8

examples/Kaleidoscope/Orc/lazy_codegen/Makefile

@@ -0,0 +1,9 @@
+.PHONY: all
+all: toy
+
+toy: toy.cpp
+	clang++ -std=c++11 toy.cpp -g -O0 -rdynamic -fno-rtti `llvm-config --cppflags --ldflags --system-libs --libs core orcjit native` -o toy
+
+.PHONY: clean
+clean:
+	rm -f toy

examples/Kaleidoscope/Orc/lazy_codegen/README.txt

@@ -0,0 +1,13 @@
+//===----------------------------------------------------------------------===/
+//                 Kaleidoscope with Orc - Initial Version
+//===----------------------------------------------------------------------===//
+
+This version of Kaleidoscope with Orc demonstrates lazy code-generation.
+Unlike the first Kaleidoscope-Orc tutorial, where code-gen was performed as soon
+as modules were added to the JIT, this tutorial adds a LazyEmittingLayer to defer
+code-generation until modules are actually referenced. All IR-generation is still
+performed up-front.
+
+This directory contain a Makefile that allow the code to be built in a
+standalone manner, independent of the larger LLVM build infrastructure. To build
+the program you will need to have 'clang++' and 'llvm-config' in your path.