[clang] [clang-repl] Fix module contamination after failed template instantiation (PR #204152)

[via cfe-commits]

github-actions[bot] wrote:

<!--PREMERGE ADVISOR COMMENT: Linux-->
# :penguin: Linux x64 Test Results

* 88230 tests passed
* 1659 tests skipped
* 1 test failed

## Failed Tests
(click on a test name to see its output)

### Clang
<details>
<summary>Clang.Interpreter/recover-template-instantiation.cpp</summary>

```
Exit Code: -9
Timeout: Reached timeout of 1200 seconds

Command Output (stdout):
--
# RUN: at line 2
cat /home/gha/actions-runner/_work/llvm-project/llvm-project/clang/test/Interpreter/recover-template-instantiation.cpp | /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/clang-repl 2>&1 | /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/FileCheck /home/gha/actions-runner/_work/llvm-project/llvm-project/clang/test/Interpreter/recover-template-instantiation.cpp
# executed command: cat /home/gha/actions-runner/_work/llvm-project/llvm-project/clang/test/Interpreter/recover-template-instantiation.cpp
# note: command had no output on stdout or stderr
# error: command reached timeout: True
# executed command: /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/clang-repl
# note: command had no output on stdout or stderr
# error: command failed with exit status: -9
# error: command reached timeout: True
# executed command: /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/FileCheck /home/gha/actions-runner/_work/llvm-project/llvm-project/clang/test/Interpreter/recover-template-instantiation.cpp
# note: command had no output on stdout or stderr
# error: command failed with exit status: -9
# error: command reached timeout: True

--

```
</details>

If these failures are unrelated to your changes (for example tests are broken or flaky at HEAD), please open an issue at https://github.com/llvm/llvm-project/issues and add the `infrastructure` label.

https://github.com/llvm/llvm-project/pull/204152