[Debugger] Introducing lldb on for llvm-krun script (#857)

Fixes #852 

This simple PR checks if the user is on a `macOS` system before
executing the interpreter in debug mode, and if that's the case, the
debug command is now modified to call `lldb` with the corrected
supported flags instead of calling `gdb`.

It also fixes a bug on `--debug-batch`.

---------

Co-authored-by: rv-jenkins <[email protected]>

Author: Robertorosmaninho

bin/llvm-krun

@@ -1,5 +1,6 @@
 #!/bin/bash
 set -e
+set -x
 
 params=()
 pretty=()
@@ -17,8 +18,8 @@ trap 'cleanup' INT TERM EXIT
 
 initializer="LblinitGeneratedTopCell{}"
 dir=.
-debug=
-debug_command=
+debug=()
+debug_command=()
 depth=-1
 verbose=0
 binary_input=false
@@ -164,22 +165,34 @@ do
     ;;
 
     --debug)
-    debug="gdb --args "
+    if [[ "$OSTYPE" == "darwin"* ]]; then
+      debug=("lldb" "--")
+    else
+      debug=("gdb" "--args")
+    fi
     shift;
     ;;
 
     --debug-command)
-    debug_command="$2"
-    if [[ -z $debug ]]; then
-      debug="gdb -x ${debug_command} --args "
+    debug_command+=("$2")
+    if [[ "$OSTYPE" == "darwin"* ]]; then
+      debug=("lldb" "-s")
     else
-      debug="${debug/--args /} -x ${debug_command} --args "
+      debug=("gdb" "-x")
     fi
+    debug+=("${debug_command[@]}")
+    debug+=("--args")
     shift;
+    shift
     ;;
 
     --debug-batch)
-    debug="gdb --batch --args "
+    if [[ "$OSTYPE" == "darwin"* ]]; then
+      debug=("lldb" "--batch" "--")
+    else
+      debug=("gdb" "batch" "--args")
+    fi
+    shift
     ;;
 
     --depth)
@@ -472,7 +485,7 @@ set +e
 if [ "$verbose" -ge 1 ]; then
   set -x
 fi
-$debug "$dir"/interpreter "$expanded_input_file" "$depth" "$output_file" "${interpreter_flags[@]}"
+"${debug[@]}" "${dir}/interpreter" "$expanded_input_file" "$depth" "$output_file" "${interpreter_flags[@]}"
 )
 EXIT=$?
 set -e