Fix warnings about tautological compares by recent Clang versions.

src/ia32/assembler-ia32.cc

Index: src/ia32/assembler-ia32.cc
diff --git a/src/ia32/assembler-ia32.cc b/src/ia32/assembler-ia32.cc
index f291b05260b141dde99cb81b394529f69ffcc2af..986395259f07822f9d54ff07c379d4d0c728d9fd 100644
--- a/src/ia32/assembler-ia32.cc
+++ b/src/ia32/assembler-ia32.cc
@@ -1501,7 +1501,7 @@ void Assembler::jmp(Handle<Code> code, RelocInfo::Mode rmode) {
 
 void Assembler::j(Condition cc, Label* L, Label::Distance distance) {
   EnsureSpace ensure_space(this);
-  ASSERT(0 <= cc && cc < 16);
+  ASSERT(0 <= cc && static_cast<int>(cc) < 16);
   if (L->is_bound()) {
     const int short_size = 2;
     const int long_size  = 6;
@@ -1533,7 +1533,7 @@ void Assembler::j(Condition cc, Label* L, Label::Distance distance) {
 
 void Assembler::j(Condition cc, byte* entry, RelocInfo::Mode rmode) {
   EnsureSpace ensure_space(this);
-  ASSERT((0 <= cc) && (cc < 16));
+  ASSERT((0 <= cc) && (static_cast<int>(cc) < 16));
   // 0000 1111 1000 tttn #32-bit disp.
   EMIT(0x0F);
   EMIT(0x80 | cc);