Revert 186302 to fix build bots.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@186305 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/driver/driver.cpp b/tools/driver/driver.cpp
index 6d81db1..48eeed9 100644
--- a/tools/driver/driver.cpp
+++ b/tools/driver/driver.cpp
@@ -303,7 +303,7 @@
     bool FoundMatch = false;
     size_t i;
 
-    for (i = 0; i < llvm::array_lengthof(suffixes); ++i) {
+    for (i = 0; i < sizeof(suffixes) / sizeof(suffixes[0]); ++i) {
       if (ProgNameRef.endswith(suffixes[i].Suffix)) {
         FoundMatch = true;
         if (suffixes[i].IsCXX)