Remove broken %_Log functionality.

src/arm64/macro-assembler-arm64.cc

Index: src/arm64/macro-assembler-arm64.cc
diff --git a/src/arm64/macro-assembler-arm64.cc b/src/arm64/macro-assembler-arm64.cc
index 0b2954e18f54ee9b78eeb5b6ff3a517e62b5876e..962853ca407abba544591c363d7e9411559102d0 100644
--- a/src/arm64/macro-assembler-arm64.cc
+++ b/src/arm64/macro-assembler-arm64.cc
@@ -1615,14 +1615,7 @@ void MacroAssembler::CallRuntime(const Runtime::Function* f,
 
   // Check that the number of arguments matches what the function expects.
   // If f->nargs is -1, the function can accept a variable number of arguments.
-  if (f->nargs >= 0 && f->nargs != num_arguments) {
-    // Illegal operation: drop the stack arguments and return undefined.
-    if (num_arguments > 0) {
-      Drop(num_arguments);
-    }
-    LoadRoot(x0, Heap::kUndefinedValueRootIndex);
-    return;
-  }
+  CHECK(f->nargs < 0 || f->nargs == num_arguments);
 
   // Place the necessary arguments.
   Mov(x0, num_arguments);