Clear the entering, exiting and internal ranges of a bundle before collecting

ranges for the instruction about to be bundled. This fixes a bug in an external
project where an assertion was triggered due to spurious 'multiple defs' within
the bundle.

Patch by Ivan Llopard. Thanks Ivan!

llvm-svn: 157632

llvm/lib/CodeGen/LiveIntervalAnalysis.cpp

@@ -1097,6 +1097,9 @@ public:
 
     BundleRanges BR = createBundleRanges(Entering, Internal, Exiting);
 
+    Entering.clear();
+    Internal.clear();
+    Exiting.clear();
     collectRanges(MI, Entering, Internal, Exiting, hasRegMaskOp, OldIdx);
     assert(!hasRegMaskOp && "Can't have RegMask operand in bundle.");