JumpPatchSites can/should easily deal with uint8 sized offsets.

src/ia32/ic-ia32.cc

Index: src/ia32/ic-ia32.cc
diff --git a/src/ia32/ic-ia32.cc b/src/ia32/ic-ia32.cc
index c2be7da1a495bb01ff7d714c358f4ff5692f6107..4a962a65fbe61b3fcdb38d1500b62f7929fb0617 100644
--- a/src/ia32/ic-ia32.cc
+++ b/src/ia32/ic-ia32.cc
@@ -1282,7 +1282,7 @@ void PatchInlinedSmiCode(Address address, InlinedSmiCheck check) {
   Address delta_address = test_instruction_address + 1;
   // The delta to the start of the map check instruction and the
   // condition code uses at the patched jump.
-  int8_t delta = *reinterpret_cast<int8_t*>(delta_address);
+  uint8_t delta = *reinterpret_cast<uint8_t*>(delta_address);
   if (FLAG_trace_ic) {
     PrintF("[  patching ic at %p, test=%p, delta=%d\n",
            address, test_instruction_address, delta);