Update clang to r339409b.

Change-Id: Ied8a188bb072c40035320acedc86164b66d920af
diff --git a/linux-x64/clang/include/llvm/MC/MCSchedule.h b/linux-x64/clang/include/llvm/MC/MCSchedule.h
index f2f1dfb..9f53a46 100644
--- a/linux-x64/clang/include/llvm/MC/MCSchedule.h
+++ b/linux-x64/clang/include/llvm/MC/MCSchedule.h
@@ -182,6 +182,10 @@
     // cycles.
     const char *CycleCounter;
 
+    // An optional name of a performance counter that can be used to measure
+    // uops.
+    const char *UopsCounter;
+
     // For each MCProcResourceDesc defined by the processor, an optional list of
     // names of performance counters that can be used to measure the resource
     // utilization.