Fix MIPS build broken by r12735 'Allow unaligned accesses for ARMv7'.

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

Index: src/mips/regexp-macro-assembler-mips.cc
diff --git a/src/mips/regexp-macro-assembler-mips.cc b/src/mips/regexp-macro-assembler-mips.cc
index 21d1ce11b5e4a4a1058093728ec486381f2ee18e..672ba0eeee0f6dd13fa20c51f142e8b44a0f4519 100644
--- a/src/mips/regexp-macro-assembler-mips.cc
+++ b/src/mips/regexp-macro-assembler-mips.cc
@@ -1103,6 +1103,11 @@ void RegExpMacroAssemblerMIPS::WriteStackPointerToRegister(int reg) {
 }
 
 
+bool RegExpMacroAssemblerMIPS::CanReadUnaligned() {
+  return false;
+}
+
+
 // Private methods:
 
 void RegExpMacroAssemblerMIPS::CallCheckStackGuardState(Register scratch) {