Update OptionGroup::SetValue to take StringRef.

Then deal with all the fallout.

Differential Revision: https://reviews.llvm.org/D24847

llvm-svn: 282265
diff --git a/lldb/source/Interpreter/OptionGroupOutputFile.cpp b/lldb/source/Interpreter/OptionGroupOutputFile.cpp
index 048036b..b9538fb 100644
--- a/lldb/source/Interpreter/OptionGroupOutputFile.cpp
+++ b/lldb/source/Interpreter/OptionGroupOutputFile.cpp
@@ -39,7 +39,7 @@
 }
 
 Error OptionGroupOutputFile::SetOptionValue(
-    uint32_t option_idx, const char *option_arg,
+    uint32_t option_idx, llvm::StringRef option_arg,
     ExecutionContext *execution_context) {
   Error error;
   const int short_option = g_option_table[option_idx].short_option;