MIPS: Fix '[regexp] implement case-insensitive unicode regexps.'

src/regexp/mips/regexp-macro-assembler-mips.cc

Index: src/regexp/mips/regexp-macro-assembler-mips.cc
diff --git a/src/regexp/mips/regexp-macro-assembler-mips.cc b/src/regexp/mips/regexp-macro-assembler-mips.cc
index 8cb0d9cf5a85ea8f028e93ed9a4700bf5846f6d7..7844f5bf6191d43fbb31b82b5bbc552267f242e0 100644
--- a/src/regexp/mips/regexp-macro-assembler-mips.cc
+++ b/src/regexp/mips/regexp-macro-assembler-mips.cc
@@ -326,7 +326,7 @@ void RegExpMacroAssemblerMIPS::CheckNotBackReferenceIgnoreCase(
     // Isolate.
 #ifdef V8_I18N_SUPPORT
     if (unicode) {
-      __ li(a3, Operand(zero_reg));
+      __ mov(a3, zero_reg);
     } else  // NOLINT
 #endif      // V8_I18N_SUPPORT
     {