Add a html-based visualizer for TurboFan graphs

tools/turbolizer/README

Index: tools/turbolizer/README
diff --git a/tools/turbolizer/README b/tools/turbolizer/README
new file mode 100644
index 0000000000000000000000000000000000000000..99548b003e3c4124447e989430e4a7ec8319be12
--- /dev/null
+++ b/tools/turbolizer/README
@@ -0,0 +1,20 @@
+Turbolizer is a HTML-based tool that visualizes optimized code along the various
+phases of Turbofan's optimization pipeline, allowing easy navigation between
+source code, Turbofan IR graphs, scheduled IR nodes and generated assembly code.
+
+Turbolizer consumes .json files that are generated per-function by d8 by passing
+the '--trace-turbo' command-line flag.
+
+Host the turbolizer locally by starting a web server that serves the contents of
+the turbolizer directory, e.g.:
+
+cd src/tools/turbolizer
+python -m SimpleHTTPServer 8000
+
+Graph visualization and manipulation based on Mike Bostock's sample code for an
+interactive tool for creating directed graphs. Original source is at
+https://github.com/metacademy/directed-graph-creator and released under the
+MIT/X license.
+
+Icons dervied from the "White Olive Collection" created by Breezi released under
+the Creative Commons BY license.