Refactoring of function types. Also fixes some library import bugs.

src/alloy/hir/hir_builder.cc

@@ -557,6 +557,13 @@ void HIRBuilder::CallIndirectTrue(
   EndBlock();
 }
 
+void HIRBuilder::CallExtern(FunctionInfo* symbol_info) {
+  Instr* i = AppendInstr(OPCODE_CALL_EXTERN_info, 0);
+  i->src1.symbol_info = symbol_info;
+  i->src2.value = i->src3.value = NULL;
+  EndBlock();
+}
+
 void HIRBuilder::Return() {
   Instr* i = AppendInstr(OPCODE_RETURN_info, 0);
   i->src1.value = i->src2.value = i->src3.value = NULL;

src/alloy/hir/hir_builder.h

@@ -74,6 +74,7 @@ public:
                 uint32_t call_flags = 0);
   void CallIndirect(Value* value, uint32_t call_flags = 0);
   void CallIndirectTrue(Value* cond, Value* value, uint32_t call_flags = 0);
+  void CallExtern(runtime::FunctionInfo* symbol_info);
   void Return();
   void ReturnTrue(Value* cond);
 

src/alloy/hir/opcodes.h

@@ -94,6 +94,7 @@ enum Opcode {
   OPCODE_CALL_TRUE,
   OPCODE_CALL_INDIRECT,
   OPCODE_CALL_INDIRECT_TRUE,
+  OPCODE_CALL_EXTERN,
   OPCODE_RETURN,
   OPCODE_RETURN_TRUE,
 

src/alloy/hir/opcodes.inl

@@ -74,6 +74,12 @@ DEFINE_OPCODE(
     OPCODE_SIG_X_V_V,
     OPCODE_FLAG_BRANCH);
 
+DEFINE_OPCODE(
+    OPCODE_CALL_EXTERN,
+    "call_extern",
+    OPCODE_SIG_X_S,
+    OPCODE_FLAG_BRANCH);
+
 DEFINE_OPCODE(
     OPCODE_RETURN,
     "return",