Fix many -Wsign-compare and -Wtautological-constant-compare warnings.

Most of the -Wsign-compare warnings are due to the fact that
enums are signed by default in the MS ABI, while the
tautological comparison warnings trigger on x86 builds where
sizeof(size_t) is 4 bytes, so N > numeric_limits<unsigned>::max()
is always false.

Differential Revision: https://reviews.llvm.org/D41256

llvm-svn: 320750
diff --git a/llvm/lib/Support/ARMAttributeParser.cpp b/llvm/lib/Support/ARMAttributeParser.cpp
index a9a0c1d..3d800eb 100644
--- a/llvm/lib/Support/ARMAttributeParser.cpp
+++ b/llvm/lib/Support/ARMAttributeParser.cpp
@@ -592,7 +592,7 @@
     bool Handled = false;
     for (unsigned AHI = 0, AHE = array_lengthof(DisplayRoutines);
          AHI != AHE && !Handled; ++AHI) {
-      if (DisplayRoutines[AHI].Attribute == Tag) {
+      if (uint64_t(DisplayRoutines[AHI].Attribute) == Tag) {
         (this->*DisplayRoutines[AHI].Routine)(ARMBuildAttrs::AttrType(Tag),
                                               Data, Offset);
         Handled = true;