Add mips64 port.

src/jsregexp.cc

Index: src/jsregexp.cc
diff --git a/src/jsregexp.cc b/src/jsregexp.cc
index 82d824ab0961846b18aaeb4c6a7eef0c907d8ad4..1566293d7affe5e40eafb03c9367f2f6ae1bf58a 100644
--- a/src/jsregexp.cc
+++ b/src/jsregexp.cc
@@ -32,6 +32,8 @@
 #include "src/arm/regexp-macro-assembler-arm.h"  // NOLINT
 #elif V8_TARGET_ARCH_MIPS
 #include "src/mips/regexp-macro-assembler-mips.h"  // NOLINT
+#elif V8_TARGET_ARCH_MIPS64
+#include "src/mips64/regexp-macro-assembler-mips64.h"  // NOLINT
 #elif V8_TARGET_ARCH_X87
 #include "src/x87/regexp-macro-assembler-x87.h"  // NOLINT
 #else
@@ -6069,6 +6071,9 @@ RegExpEngine::CompilationResult RegExpEngine::Compile(
 #elif V8_TARGET_ARCH_MIPS
   RegExpMacroAssemblerMIPS macro_assembler(mode, (data->capture_count + 1) * 2,
                                            zone);
+#elif V8_TARGET_ARCH_MIPS64
+  RegExpMacroAssemblerMIPS macro_assembler(mode, (data->capture_count + 1) * 2,
+                                           zone);
 #elif V8_TARGET_ARCH_X87
   RegExpMacroAssemblerX87 macro_assembler(mode, (data->capture_count + 1) * 2,
                                           zone);