Adding support for MInt{128} (#1160)

This PR extends our Machine Integers support to also support 128 bits
for k hashing and for equality function `==K`.
This is necessary for one of our light semantics in Pi2.

runtime/collections/hash.cpp

@@ -134,6 +134,12 @@ void k_hash(block *arg, void *h) {
             add_hash64(h, *intptr);
             break;
           }
+          case MINT_LAYOUT + 128: {
+            auto *intptr = (uint64_t *)(argintptr + offset);
+            add_hash64(h, intptr[0]);
+            add_hash64(h, intptr[1]);
+            break;
+          }
           case MINT_LAYOUT + 160: {
             auto *intptr = (uint64_t *)(argintptr + offset);
             add_hash64(h, intptr[0]);

runtime/collections/kelemle.cpp

@@ -143,6 +143,16 @@ bool hook_KEQUAL_eq(block *arg1, block *arg2) {
           }
           break;
         }
+        case MINT_LAYOUT + 128: {
+          auto *child1ptr = (int64_t *)(child1intptr);
+          auto *child2ptr = (int64_t *)(child2intptr);
+          bool cmp
+              = child1ptr[0] == child2ptr[0] && child1ptr[1] == child2ptr[1];
+          if (!cmp) {
+            return false;
+          }
+          break;
+        }
         case MINT_LAYOUT + 160: {
           auto *child1ptr = (int64_t *)(child1intptr);
           auto *child2ptr = (int64_t *)(child2intptr);