Remove FunctionType (#2510)

Function signatures were previously redundantly stored on Function
objects as well as on FunctionType objects. These two signature
representations had to always be kept in sync, which was error-prone
and needlessly complex. This PR takes advantage of the new ability of
Type to represent multiple value types by consolidating function
signatures as a pair of Types (params and results) stored on the
Function object.

Since there are no longer module-global named function types,
significant changes had to be made to the printing and emitting of
function types, as well as their parsing and manipulation in various
passes.

The C and JS APIs and their tests also had to be updated to remove
named function types.

1 files changed, 3 insertions, 6 deletions

diff --git a/src/tools/wasm-reduce.cpp b/src/tools/wasm-reduce.cpp
index 3e1e464f8..274b6de29 100644
--- a/src/tools/wasm-reduce.cpp
+++ b/src/tools/wasm-reduce.cpp
@@ -866,8 +866,7 @@ struct Reducer
       auto* func = module->functions[0].get();
       // We can't remove something that might have breaks to it.
       if (!func->imported() && !Properties::isNamedControlFlow(func->body)) {
-        auto funcType = func->type;
-        auto funcResult = func->result;
+        auto funcSig = func->sig;
         auto* funcBody = func->body;
         for (auto* child : ChildIterator(func->body)) {
           if (!(child->type.isConcrete() || child->type == none)) {
@@ -875,8 +874,7 @@ struct Reducer
           }
           // Try to replace the body with the child, fixing up the function
           // to accept it.
-          func->type = Name();
-          func->result = child->type;
+          func->sig.results = child->type;
           func->body = child;
           if (writeAndTestReduction()) {
             // great, we succeeded!
@@ -885,8 +883,7 @@ struct Reducer
             break;
           }
           // Undo.
-          func->type = funcType;
-          func->result = funcResult;
+          func->sig = funcSig;
           func->body = funcBody;
         }
       }