Compare DataLayout by Value, not by pointer.

This fixes spurious warnings in llvm-link about the datalayout not matching.

Thanks to Zalman Stern for reporting the bug!

llvm-svn: 202276
diff --git a/llvm/lib/IR/DataLayout.cpp b/llvm/lib/IR/DataLayout.cpp
index 7089b7b..162f3d3 100644
--- a/llvm/lib/IR/DataLayout.cpp
+++ b/llvm/lib/IR/DataLayout.cpp
@@ -354,6 +354,16 @@
     reset("");
 }
 
+bool DataLayout::operator==(const DataLayout &Other) const {
+  bool Ret = LittleEndian == Other.LittleEndian &&
+             StackNaturalAlign == Other.StackNaturalAlign &&
+             ManglingMode == Other.ManglingMode &&
+             LegalIntWidths == Other.LegalIntWidths &&
+             Alignments == Other.Alignments && Pointers == Pointers;
+  assert(Ret == (getStringRepresentation() == Other.getStringRepresentation()));
+  return Ret;
+}
+
 void
 DataLayout::setAlignment(AlignTypeEnum align_type, unsigned abi_align,
                          unsigned pref_align, uint32_t bit_width) {