Centralize instruction-set pointer-size, alignment, 64b-width code
in instruction_set.h/cc

This allows to clean up some places that currently make explicit
comparisons.

Change-Id: I0dcc924c52fa53306f706aceea93a2d4a655c5df
diff --git a/runtime/utils.h b/runtime/utils.h
index dbc3ab7..5def66b 100644
--- a/runtime/utils.h
+++ b/runtime/utils.h
@@ -62,12 +62,20 @@
   return IsAligned<n>(reinterpret_cast<const uintptr_t>(x));
 }
 
+template<typename T>
+static inline bool IsAlignedParam(T x, int n) {
+  return (x & (n - 1)) == 0;
+}
+
 #define CHECK_ALIGNED(value, alignment) \
   CHECK(::art::IsAligned<alignment>(value)) << reinterpret_cast<const void*>(value)
 
 #define DCHECK_ALIGNED(value, alignment) \
   DCHECK(::art::IsAligned<alignment>(value)) << reinterpret_cast<const void*>(value)
 
+#define DCHECK_ALIGNED_PARAM(value, alignment) \
+  DCHECK(::art::IsAlignedParam(value, alignment)) << reinterpret_cast<const void*>(value)
+
 // Check whether an N-bit two's-complement representation can hold value.
 static inline bool IsInt(int N, word value) {
   CHECK_LT(0, N);