Add TargetInfo::useNeXTRuntimeAsDefault
 - Used to autoselect runtime when neither -fnext-runtime nor
   -fgnu-runtime is specified.
 - Default impl is false, all darwin targets set it to true.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@55231 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Basic/Targets.cpp b/lib/Basic/Targets.cpp
index a04ce36..fae0a71 100644
--- a/lib/Basic/Targets.cpp
+++ b/lib/Basic/Targets.cpp
@@ -501,6 +501,8 @@
     PPC32TargetInfo::getTargetDefines(Defines);
     getDarwinDefines(Defines);
   }
+
+  virtual bool useNeXTRuntimeAsDefault() const { return true; }
 };
 } // end anonymous namespace.
 
@@ -512,6 +514,8 @@
     PPC64TargetInfo::getTargetDefines(Defines);
     getDarwinDefines(Defines);
   }
+
+  virtual bool useNeXTRuntimeAsDefault() const { return true; }
 };
 } // end anonymous namespace.
 
@@ -656,6 +660,7 @@
     X86_32TargetInfo::getTargetDefines(Defines);
     getDarwinDefines(Defines);
   }
+  virtual bool useNeXTRuntimeAsDefault() const { return true; }
 };
 } // end anonymous namespace
 
@@ -735,6 +740,8 @@
     X86_64TargetInfo::getTargetDefines(Defines);
     getDarwinDefines(Defines);
   }
+
+  virtual bool useNeXTRuntimeAsDefault() const { return true; }
 };
 } // end anonymous namespace.