getClosestStaticTargetForModule was replaced with lookupTarget

Build fix for LLVM r77111.

gen/llvmhelpers.cpp

@@ -1,6 +1,5 @@
 #include "gen/llvmhelpers.h"
 #include "gen/llvm.h"
-#include "llvm/Target/TargetMachineRegistry.h"
 
 #include "mars.h"
 #include "init.h"

gen/main.cpp

@@ -442,7 +442,7 @@ LDC_TARGETS
     if (mArch.empty())
     {
         std::string Err;
-        theTarget = llvm::TargetRegistry::getClosestStaticTargetForModule(mod, Err);
+        theTarget = llvm::TargetRegistry::lookupTarget(mod.getTargetTriple(), false, false, Err);
         if (theTarget == 0)
         {
             error("failed to auto-select target: %s, please use the -march option", Err.c_str());