wasm2c: Use wrappers for function references (#2465)

Clang 17(?) tightened UBSAN checks, so that you now get this:

```
- test/wasm2c/spec/call_indirect.txt
  expected error code 0, got 1.
  STDERR MISMATCH:
  --- expected
  +++ actual
  @@ -0,0 +1,3 @@
  +out/test/wasm2c/spec/call_indirect/call_indirect.0.c:2144:12: runtime error: call to function w2c_call__indirect__0__wasm_f0 through pointer to incorrect function type 'unsigned int (*)(void *)'
  +/home/runner/work/wabt/wabt/out/test/wasm2c/spec/call_indirect/call_indirect.0.c:1925: note: w2c_call__indirect__0__wasm_f0 defined here
  +SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior out/test/wasm2c/spec/call_indirect/call_indirect.0.c:2144:12 
  STDOUT MISMATCH:
  --- expected
  +++ actual
  @@ -1 +0,0 @@
  -134/134 tests passed.
```

This happens because emitted functions use a typed module instance,
while function references use a `void*` instance. It is UB in C to call
the former with the latter, so clang is correct here.

We had to pick one of two ways to fix this: either emit `void*` wrapper
functions that do the appropriate downcasting for any module functions
that go into a table (potentially including imported functions), or the
approach that takes significantly less effort of changing everything to
`void*` and downcasting internally. ~~We obviously chose the latter.~~
We eventually started emitting wrapper functions.

1 files changed, 1 insertions, 1 deletions

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 92b5a088..99ffb6eb 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -99,7 +99,7 @@ jobs:
 
   sanitize:
     name: sanitize
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04
     env:
       USE_NINJA: "1"
       CC: "clang"