MIPS: Landing: [hydrogen] optimize switch with string clauses.

src/mips/lithium-codegen-mips.h

Index: src/mips/lithium-codegen-mips.h
diff --git a/src/mips/lithium-codegen-mips.h b/src/mips/lithium-codegen-mips.h
index 5d4a057feb4e931112e0fad63295404c2cada5a9..57d3d9b853d181cebbeb89081b27db38e82dfe38 100644
--- a/src/mips/lithium-codegen-mips.h
+++ b/src/mips/lithium-codegen-mips.h
@@ -299,6 +299,13 @@ class LCodeGen BASE_EMBEDDED {
                          Label* is_not_object,
                          Label* is_object);
 
+  // Emits optimized code for %_IsString(x).  Preserves input register.
+  // Returns the condition on which a final split to
+  // true and false label should be made, to optimize fallthrough.
+  Condition EmitIsString(Register input,
+                         Register temp1,
+                         Label* is_not_string);
+
   // Emits optimized code for %_IsConstructCall().
   // Caller should branch on equal condition.
   void EmitIsConstructCall(Register temp1, Register temp2);