[DataLayout] Use linear scan to determine integer alignment (NFC)

The number of alignment entries is usually very small (5-7), so
it is more efficient to use a linear scan than a binary search.

Author: nikic

llvm/lib/IR/DataLayout.cpp

@@ -694,7 +694,12 @@ void DataLayout::setPointerSpec(uint32_t AddrSpace, uint32_t BitWidth,
 
 Align DataLayout::getIntegerAlignment(uint32_t BitWidth,
                                       bool abi_or_pref) const {
-  auto I = lower_bound(IntSpecs, BitWidth, LessPrimitiveBitWidth());
+  auto I = IntSpecs.begin();
+  for (; I != IntSpecs.end(); ++I) {
+    if (I->BitWidth >= BitWidth)
+      break;
+  }
+
   // If we don't have an exact match, use alignment of next larger integer
   // type. If there is none, use alignment of largest integer type by going
   // back one element.