Revert 167755/167760. We don't want to emit crash diagnostics on command-line syntax errors.

llvm-svn: 167849
diff --git a/llvm/lib/Support/ErrorHandling.cpp b/llvm/lib/Support/ErrorHandling.cpp
index 3c335a6..e6cc57d 100644
--- a/llvm/lib/Support/ErrorHandling.cpp
+++ b/llvm/lib/Support/ErrorHandling.cpp
@@ -81,10 +81,7 @@
   // files registered with RemoveFileOnSignal.
   sys::RunInterruptHandlers();
 
-  // When reporting a fatal error, exit with status 70.  For BSD systems this
-  // is defined as an internal software error.  This notifies the driver to
-  // report diagnostics information.
-  exit(70);
+  exit(1);
 }
 
 void llvm::llvm_unreachable_internal(const char *msg, const char *file,