Move boxString to a header file

Not sure how much it helps, but it's mostly just a wrapper around
new boxedstring.

Also, I don't think it needs to be in inline/ any more since we
will always box strings during codegen rather than emit calls
to boxString.

src/runtime/inline/boxing.cpp

@@ -30,15 +30,6 @@ extern "C" Box* createList() {
     return new BoxedList();
 }
 
-BoxedString* boxString(llvm::StringRef s) {
-    if (s.size() <= 1) {
-        if (s.size() == 0)
-            return EmptyString;
-        return characters[s.data()[0] & UCHAR_MAX];
-    }
-    return new (s.size()) BoxedString(s);
-}
-
 BoxedString* boxStringTwine(const llvm::Twine& t) {
     llvm::SmallString<256> Vec;
     return boxString(t.toStringRef(Vec));

src/runtime/types.h

@@ -915,6 +915,15 @@ Box* codeForCLFunction(CLFunction*);
 CLFunction* clfunctionFromCode(Box* code);
 
 Box* getFrame(int depth);
+
+inline BoxedString* boxString(llvm::StringRef s) {
+    if (s.size() <= 1) {
+        if (s.size() == 0)
+            return EmptyString;
+        return characters[s.data()[0] & UCHAR_MAX];
+    }
+    return new (s.size()) BoxedString(s);
+}
 }
 
 #endif