PNaCl: Add pass to expand out Clang-generated umul.with.overflow calls

This adds a pass, ExpandMulWithOverflow, to expand out the
llvm.umul.with.overflow calls that Clang generates to implement an
overflow check for C++'s new[] operator.

BUG=https://code.google.com/p/nativeclient/issues/detail?id=3434
TEST=expand-mul-with-overflow.ll

Review URL: https://codereview.chromium.org/14649027

1 files changed, 1 insertions, 0 deletions

diff --git a/tools/opt/opt.cpp b/tools/opt/opt.cpp
index 94ff313937..3179e17733 100644
--- a/tools/opt/opt.cpp
+++ b/tools/opt/opt.cpp
@@ -589,6 +589,7 @@ int main(int argc, char **argv) {
   initializeExpandConstantExprPass(Registry);
   initializeExpandCtorsPass(Registry);
   initializeExpandGetElementPtrPass(Registry);
+  initializeExpandMulWithOverflowPass(Registry);
   initializeExpandTlsPass(Registry);
   initializeExpandTlsConstantExprPass(Registry);
   initializeExpandVarArgsPass(Registry);