[Clang] Fix error recovery for default arguments (#208868)
Fixes #205718
### Description
This PR fixes an issue where Clang incorrectly skips the creation of a
parameter when an error occurs in a default argument that involves a GNU
statement expression (`({ ... })`).
Previously, if the default expression evaluation failed within a
statement expression, the error recovery was not handled properly,
leading to the parameter being dropped. This fix ensures that the
parameter is correctly created and error recovery proceeds as expected.
### Testing
Added/Updated test cases in
`clang/test/SemaCXX/default-arg-error-recovery.cpp` to cover invalid
default arguments inside statement expressions.
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