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

src/compiler/linkage-impl.h

Index: src/compiler/linkage-impl.h
diff --git a/src/compiler/linkage-impl.h b/src/compiler/linkage-impl.h
index 76b40faf350965291742520f2d37f695c8605c46..0a18f6e8db21301d833ab31ed8746e745d11d40f 100644
--- a/src/compiler/linkage-impl.h
+++ b/src/compiler/linkage-impl.h
@@ -204,11 +204,13 @@ class LinkageHelper {
 
     // Add register and/or stack parameter(s).
     const int parameter_count = static_cast<int>(msig->parameter_count());
+    int stack_offset = LinkageTraits::CStackBackingStoreLength();
     for (int i = 0; i < parameter_count; i++) {
       if (i < LinkageTraits::CRegisterParametersLength()) {
         locations.AddParam(regloc(LinkageTraits::CRegisterParameter(i)));
       } else {
-        locations.AddParam(stackloc(-1 - i));
+        locations.AddParam(stackloc(-1 - stack_offset));
+        stack_offset++;
       }
     }