Otherwise debug-info is stripped, which influences the language of the
current frame.
Also, set explicit breakpoint because Windows seems to not obey the
debugtrap.
Log from failing test on Windows:
```
(lldb) command source -s 0 'lit-lldb-init-quiet'
Executing commands in 'D:\test\lit-lldb-init-quiet'.
(lldb) command source -C --silent-run true lit-lldb-init
(lldb) target create "main.out"
Current executable set to 'D:\test\main.out' (x86_64).
(lldb) settings set interpreter.stop-command-source-on-error false
(lldb) command source -s 0 'with-target.input'
Executing commands in 'D:\test\with-target.input'.
(lldb) expr blah
^
error: use of undeclared identifier 'blah'
note: Falling back to default language. Ran expression as 'Objective C++'.
(lldb) run
Process 29404 launched: 'D:\test\main.out' (x86_64)
Process 29404 stopped
* thread #1, stop reason = Exception 0x80000003 encountered at address 0x7ff7b3df7189
frame #0: 0x00007ff7b3df718a main.out
-> 0x7ff7b3df718a: xorl %eax, %eax
0x7ff7b3df718c: popq %rcx
0x7ff7b3df718d: retq
0x7ff7b3df718e: int3
(lldb) expr blah
^
error: use of undeclared identifier 'blah'
note: Falling back to default language. Ran expression as 'Objective C++'.
(lldb) expr -l objc -- blah
^
error: use of undeclared identifier 'blah'
note: Expression evaluation in pure Objective-C not supported. Ran expression as 'Objective C++'.
(lldb) expr -l c -- blah
^
error: use of undeclared identifier 'blah'
note: Expression evaluation in pure C not supported. Ran expression as 'ISO C++'.
```
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