[turbofan] Add basic support for calling to (a subset of) C functions.

src/compiler/mips/code-generator-mips.cc

Index: src/compiler/mips/code-generator-mips.cc
diff --git a/src/compiler/mips/code-generator-mips.cc b/src/compiler/mips/code-generator-mips.cc
index 3afb86af45556328c1af7f805c3cf578e4eb216a..f7c1e01f80153325ded7c75424b1ab1f737790b9 100644
--- a/src/compiler/mips/code-generator-mips.cc
+++ b/src/compiler/mips/code-generator-mips.cc
@@ -463,6 +463,22 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       __ Jump(at);
       break;
     }
+    case kArchPrepareCallCFunction: {
+      int const num_parameters = MiscField::decode(instr->opcode());
+      __ PrepareCallCFunction(num_parameters, kScratchReg);
+      break;
+    }
+    case kArchCallCFunction: {
+      int const num_parameters = MiscField::decode(instr->opcode());
+      if (instr->InputAt(0)->IsImmediate()) {
+        ExternalReference ref = i.InputExternalReference(0);
+        __ CallCFunction(ref, num_parameters);
+      } else {
+        Register func = i.InputRegister(0);
+        __ CallCFunction(func, num_parameters);
+      }
+      break;
+    }
     case kArchJmp:
       AssembleArchJump(i.InputRpo(0));
       break;