Binaryen wasm-opt.js pthreads build

diff.diff

diff --git a/CMakeLists.txt b/CMakeLists.txt
index def330b27..01ac747b9 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -336,12 +336,12 @@ if(EMSCRIPTEN)
 
   add_link_flag("-sALLOW_MEMORY_GROWTH")
   add_link_flag("-sSTACK_SIZE=5MB")
-  if(EMSCRIPTEN_ENABLE_WASM_EH)
-    add_compile_flag("-fwasm-exceptions")
-  else()
-    add_compile_flag("-sDISABLE_EXCEPTION_CATCHING=0")
-    add_link_flag("-sDISABLE_EXCEPTION_CATCHING=0")
-  endif()
+  add_compile_flag("-fwasm-exceptions")
+  add_compile_flag("-pthread")
+  add_link_flag("-pthread")
+  add_link_flag("-PTHREAD_POOL_SIZE=navigator.hardwareConcurrency")
+  add_link_flag("-Wno-pthreads-mem-growth")
+  add_link_flag("-sMALLOC=mimalloc")
   # In the browser, there is no natural place to provide commandline arguments
   # for a commandline tool, so let the user run the main entry point themselves
   # and pass in the arguments there.
@@ -359,7 +359,7 @@ if(EMSCRIPTEN)
     add_link_flag("-sSINGLE_FILE")
   endif()
     # in opt builds, LTO helps so much (>20%) it's worth slow compile times
-    add_nondebug_compile_flag("-flto")
+    # add_nondebug_compile_flag("-flto")
   endif()
 
 # clang doesn't print colored diagnostics when invoked from Ninja
diff --git a/src/support/threads.cpp b/src/support/threads.cpp
index e61769a84..3247ea388 100644
--- a/src/support/threads.cpp
+++ b/src/support/threads.cpp
@@ -139,15 +139,11 @@ void ThreadPool::initialize(size_t num) {
 }
 
 size_t ThreadPool::getNumCores() {
-#ifdef __EMSCRIPTEN__
-  return 1;
-#else
   size_t num = std::max(1U, std::thread::hardware_concurrency());
   if (getenv("BINARYEN_CORES")) {
     num = std::stoi(getenv("BINARYEN_CORES"));
   }
   return num;
-#endif
 }
 
 ThreadPool* ThreadPool::get() {