Don't minify __stack_pointer import (#2219)

This is core import like __memory_base and __table_base.

Author: sbc100

src/passes/MinifyImportsAndExports.cpp

@@ -145,7 +145,7 @@ struct MinifyImportsAndExports : public Pass {
     std::map<Name, Name> oldToNew;
     auto process = [&](Name& name) {
       // do not minifiy special imports, they must always exist
-      if (name == MEMORY_BASE || name == TABLE_BASE) {
+      if (name == MEMORY_BASE || name == TABLE_BASE || name == STACK_POINTER) {
         return;
       }
       auto newName = names.getName(soFar++);

src/shared-constants.h

@@ -25,6 +25,7 @@ extern Name GROW_WASM_MEMORY;
 extern Name WASM_CALL_CTORS;
 extern Name MEMORY_BASE;
 extern Name TABLE_BASE;
+extern Name STACK_POINTER;
 extern Name GET_TEMP_RET0;
 extern Name SET_TEMP_RET0;
 extern Name NEW_SIZE;

src/wasm/wasm-emscripten.cpp

@@ -65,7 +65,7 @@ Global* EmscriptenGlueGenerator::getStackPointerGlobal() {
   // linker could export it by name?
   for (auto& g : wasm.globals) {
     if (g->imported()) {
-      if (g->base == "__stack_pointer") {
+      if (g->base == STACK_POINTER) {
         return g.get();
       }
     } else if (!isExported(wasm, g->name)) {

src/wasm/wasm.cpp

@@ -48,6 +48,7 @@ Name GROW_WASM_MEMORY("__growWasmMemory");
 Name WASM_CALL_CTORS("__wasm_call_ctors");
 Name MEMORY_BASE("__memory_base");
 Name TABLE_BASE("__table_base");
+Name STACK_POINTER("__stack_pointer");
 Name GET_TEMP_RET0("getTempRet0");
 Name SET_TEMP_RET0("setTempRet0");
 Name NEW_SIZE("newSize");