Print column info in backtraces et al. if available

This patch allows LLDB to print column info in backtraces et al. if
available, which is useful when the backtrace contains a frame like
the following:

  f(can_crash(0), can_crash(1));

Differential Revision: https://reviews.llvm.org/D51661

llvm-svn: 341506
diff --git a/lldb/source/Core/Debugger.cpp b/lldb/source/Core/Debugger.cpp
index 17bec03..2fd7ff4 100644
--- a/lldb/source/Core/Debugger.cpp
+++ b/lldb/source/Core/Debugger.cpp
@@ -121,7 +121,8 @@
   "${module.file.basename}{`${function.name-without-args}"                     \
   "{${frame.no-debug}${function.pc-offset}}}}"
 
-#define FILE_AND_LINE "{ at ${line.file.basename}:${line.number}}"
+#define FILE_AND_LINE                                                          \
+  "{ at ${line.file.basename}:${line.number}{:${line.column}}}"
 #define IS_OPTIMIZED "{${function.is-optimized} [opt]}"
 
 #define DEFAULT_THREAD_FORMAT                                                  \