[clang] [llvm] [WebAssembly] Represent reference types as TargetExtType (PR #203165)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-x86_64-darwin` running on `doug-worker-3` while building `clang,llvm` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/23/builds/20673

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 6 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'Clang :: CodeGen/WebAssembly/wasm-funcref-to-ptr-error.c' FAILED ********************
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 1
not /Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/bin/clang -cc1 -internal-isystem /Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/lib/clang/23/include -nostdsysteminc -triple wasm32 -target-feature +reference-types -S -o /dev/null /Volumes/RAMDisk/buildbot-root/x86_64-darwin/llvm-project/clang/test/CodeGen/WebAssembly/wasm-funcref-to-ptr-error.c 2>&1 | /Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/bin/FileCheck /Volumes/RAMDisk/buildbot-root/x86_64-darwin/llvm-project/clang/test/CodeGen/WebAssembly/wasm-funcref-to-ptr-error.c
# executed command: not /Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/bin/clang -cc1 -internal-isystem /Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/lib/clang/23/include -nostdsysteminc -triple wasm32 -target-feature +reference-types -S -o /dev/null /Volumes/RAMDisk/buildbot-root/x86_64-darwin/llvm-project/clang/test/CodeGen/WebAssembly/wasm-funcref-to-ptr-error.c
# note: command had no output on stdout or stderr
# executed command: /Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/bin/FileCheck /Volumes/RAMDisk/buildbot-root/x86_64-darwin/llvm-project/clang/test/CodeGen/WebAssembly/wasm-funcref-to-ptr-error.c
# .---command stderr------------
# | /Volumes/RAMDisk/buildbot-root/x86_64-darwin/llvm-project/clang/test/CodeGen/WebAssembly/wasm-funcref-to-ptr-error.c:13:11: error: CHECK: expected string not found in input
# | // CHECK: error: a funcref can only be converted to a pointer to be directly called; the resulting pointer cannot otherwise be used
# |           ^
# | <stdin>:1:1: note: scanning from here
# | error: unable to create target: 'No available targets are compatible with triple "wasm32"'
# | ^
# | 
# | Input file: <stdin>
# | Check file: /Volumes/RAMDisk/buildbot-root/x86_64-darwin/llvm-project/clang/test/CodeGen/WebAssembly/wasm-funcref-to-ptr-error.c
# | 
# | -dump-input=help explains the following input dump.
# | 
# | Input was:
# | <<<<<<
# |           1: error: unable to create target: 'No available targets are compatible with triple "wasm32"' 
# | check:13     X~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ error: no match found
# |           2: 1 error generated. 
# | check:13     ~~~~~~~~~~~~~~~~~~~
# | >>>>>>
# `-----------------------------
# error: command failed with exit status: 1

--

********************


```

</details>

https://github.com/llvm/llvm-project/pull/203165