Fix IRBuilder on local operations outside of a function context (#7183)

IRBuilder needs to check for a function context before doing
func->getLocalType(). Without such a check, a bad binary with a local
operation in say a global init would lead to a crash.

We don't actually need this for local.set, unlike tee and get, since
it doesn't call getLocalType, but this PR adds that too for consistency
of errors.

No other operations in IRBuilder were missing this check aside from
local operations.

Fixes #7178

Author: kripken

src/wasm/wasm-ir-builder.cpp

@@ -1259,11 +1259,17 @@ Result<> IRBuilder::makeCallIndirect(Name table, HeapType type, bool isReturn) {
 }
 
 Result<> IRBuilder::makeLocalGet(Index local) {
+  if (!func) {
+    return Err{"local.get is only valid in a function context"};
+  }
   push(builder.makeLocalGet(local, func->getLocalType(local)));
   return Ok{};
 }
 
 Result<> IRBuilder::makeLocalSet(Index local) {
+  if (!func) {
+    return Err{"local.set is only valid in a function context"};
+  }
   LocalSet curr;
   curr.index = local;
   CHECK_ERR(visitLocalSet(&curr));
@@ -1272,6 +1278,9 @@ Result<> IRBuilder::makeLocalSet(Index local) {
 }
 
 Result<> IRBuilder::makeLocalTee(Index local) {
+  if (!func) {
+    return Err{"local.tee is only valid in a function context"};
+  }
   LocalSet curr;
   curr.index = local;
   CHECK_ERR(visitLocalSet(&curr));

test/lit/binary/global-local-get.test

@@ -0,0 +1,10 @@
+RUN: not wasm-opt --debug %s.wasm 2>&1 | filecheck %s
+
+;; Check that we get the expected error for an input binary that looks like
+;; this:
+;;
+;;  (module
+;;    (global $g i32 (local.get 0))
+;;  )
+
+;; CHECK: local.get is only valid in a function context

test/lit/binary/global-local-get.test.wasm

@@ -0,0 +1,10 @@
+RUN: not wasm-opt --debug %s.wasm 2>&1 | filecheck %s
+
+;; Check that we get the expected error for an input binary that looks like
+;; this:
+;;
+;;  (module
+;;    (global $g i32 (local.set 0 (i32.const 1)))
+;;  )
+
+;; CHECK: local.set is only valid in a function context

test/lit/binary/global-local-set.test

@@ -0,0 +1,10 @@
+RUN: not wasm-opt --debug %s.wasm 2>&1 | filecheck %s
+
+;; Check that we get the expected error for an input binary that looks like
+;; this:
+;;
+;;  (module
+;;    (global $g i32 (local.tee 0 (i32.const 1)))
+;;  )
+
+;; CHECK: local.tee is only valid in a function context