The fix is to append a newline to the source being evaluated.
Without this patch, the following commands **print no output, no errors**.
```
(lldb) script if "foo" in lldb.frame.name: print(lldb.thread)
(lldb) script for f in lldb.thread: print(f.name)
```
The issue is with `code.InteractiveConsole.runsource()`. A trailing newline is
needed for these expressions to be evaluated. I don't know why this is, the
docs don't mention anything.
From a python repl, the following samples show that a terminal newline allows
statements containing flow control to fully execute.
```
>>> import code
>>> repl = code.InteractiveConsole()
>>> repl.runsource("if True: print(1)")
True
>>> repl.runsource("if True: print(1)\n")
1
False
```
Notes:
From an interactive python repl, the output is not printed immediately. The
user is required to enter a blank line following the first.
```
>>> if True: print(1)
...
1
```
However, `python -c 'if True: print(1)'` works without needing a newline.
Reviewed By: JDevlieghere
Differential Revision: https://reviews.llvm.org/D127586
Make it possible to run the script command with a different language
than currently selected.
$ ./bin/lldb -l python
(lldb) script -l lua
>>> io.stdout:write("Hello, World!\n")
Hello, World!
When passing the language option and a raw command, you need to separate
the flag from the script code with --.
$ ./bin/lldb -l python
(lldb) script -l lua -- io.stdout:write("Hello, World!\n")
Hello, World!
Differential revision: https://reviews.llvm.org/D86996
