This is my Driver refactoring patch. 

The major changes are:
1) LinkerOptions has been merged into TargetInfo
2) LinkerInvocation has been merged into Driver
3) Drivers no longer convert arguments into an intermediate (core) argument 
   list, but instead create a TargetInfo object and call setter methods on 
   it. This is only how in-process linking would work. That is, you can 
   programmatically set up a TargetInfo object which controls the linking.
4) Lots of tweaks to test suite to work with driver changes
5) Add the DarwinDriver
6) I heavily doxygen commented TargetInfo.h

Things to do after this patch is committed:
a) Consider renaming TargetInfo, given its new roll. 
b) Consider pulling the list of input files out of TargetInfo. This will 
   enable in-process clients to create one TargetInfo the re-use it with 
   different input file lists.
c) Work out a way for Drivers to format the warnings and error done in 
   core linking.

llvm-svn: 178776
diff --git a/lld/lib/Core/SymbolTable.cpp b/lld/lib/Core/SymbolTable.cpp
index 36e52d8..4ded5a6 100644
--- a/lld/lib/Core/SymbolTable.cpp
+++ b/lld/lib/Core/SymbolTable.cpp
@@ -13,7 +13,6 @@
 #include "lld/Core/DefinedAtom.h"
 #include "lld/Core/File.h"
 #include "lld/Core/InputFiles.h"
-#include "lld/Core/LinkerOptions.h"
 #include "lld/Core/LLVM.h"
 #include "lld/Core/Resolver.h"
 #include "lld/Core/SharedLibraryAtom.h"
@@ -184,8 +183,7 @@
             useNew = false;
           }
           else {
-            if (_targetInfo.getLinkerOptions().
-                    _warnIfCoalesableAtomsHaveDifferentCanBeNull) {
+            if (_targetInfo.warnIfCoalesableAtomsHaveDifferentCanBeNull()) {
               // FIXME: need diagonstics interface for writing warning messages
               llvm::errs() << "lld warning: undefined symbol "
                            << existingUndef->name()
@@ -210,8 +208,7 @@
           bool sameName = curShLib->loadName().equals(newShLib->loadName());
           if ( !sameName ) {
             useNew = false;
-            if (_targetInfo.getLinkerOptions().
-                  _warnIfCoalesableAtomsHaveDifferentLoadName) {
+            if (_targetInfo.warnIfCoalesableAtomsHaveDifferentLoadName()) {
               // FIXME: need diagonstics interface for writing warning messages
               llvm::errs() << "lld warning: shared library symbol "
                            << curShLib->name()
@@ -223,8 +220,7 @@
           }
           else if ( ! sameNullness ) {
             useNew = false;
-            if (_targetInfo.getLinkerOptions().
-                    _warnIfCoalesableAtomsHaveDifferentCanBeNull) {
+            if (_targetInfo.warnIfCoalesableAtomsHaveDifferentCanBeNull()) {
               // FIXME: need diagonstics interface for writing warning messages
               llvm::errs() << "lld warning: shared library symbol "
                            << curShLib->name()