br_table optimizations (#1502)

Inspired by #1501

 * remove unneeded appearances of the default switch target (at the front or back of the list of targets)
 * optimize a switch with 0, 1 or 2 targets into an if or if-chain
 * optimize a br_if br pair when they have the same target

Makes e.g. fastcomp libc++ 2% smaller. Noticeable improvements on other things like box2d etc.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/passes/pass.cpp b/src/passes/pass.cpp
index be7365998..38a21fae8 100644
--- a/src/passes/pass.cpp
+++ b/src/passes/pass.cpp
@@ -197,6 +197,7 @@ static void dumpWast(Name name, Module* wasm) {
   // write out the wast
   static int counter = 0;
   auto fullName = std::string("byn-") + std::to_string(counter++) + "-" + name.str + ".wasm";
+  Colors::disable();
   ModuleWriter writer;
   writer.setBinary(false); // TODO: add an option for binary
   writer.write(*wasm, fullName);