[lldb/Lua] Use the debugger's output and error file for Lua's I/O library.

Add support for changing the stdout and stderr file in Lua's I/O library
and hook it up with the debugger's output and error file respectively
for the interactive Lua interpreter.

https://reviews.llvm.org/D82273

lldb/test/Shell/ScriptInterpreter/Lua/io.test

@@ -0,0 +1,16 @@
+# REQUIRES: lua
+# UNSUPPORTED: lldb-repro
+#
+# RUN: cat %s | %lldb --script-language lua 2> %t.stderr > %t.stdout
+# RUN: cat %t.stdout | FileCheck %s --check-prefix STDOUT
+# RUN: cat %t.stderr | FileCheck %s --check-prefix STDERR
+script
+file = lldb.SBFile(2, "w", false)
+lldb.debugger:SetOutputFile(file)
+io.write(95000 + 126, "\n")
+quit
+script
+io.write(95000 + 14, "\n")
+# STDOUT: 95126
+# STDOUT-NOT: 95014
+# STDERR: 95014