Factor out looking up the llvm function for the julia function

This is useful when you actually want the function object, rather
than just looking at the IR.

src/codegen.cpp

@@ -826,18 +826,18 @@ const jl_value_t *jl_dump_llvmf(void *f, bool dumpasm)
 }
 
 extern "C" DLLEXPORT
-const jl_value_t *jl_dump_function(jl_function_t *f, jl_tuple_t *types, bool dumpasm, bool dumpwrapper)
+void *jl_get_llvmf(jl_function_t *f, jl_tuple_t *types, bool getwrapper)
 {
  jl_function_t *sf = f;
  if (types != NULL) {
  if (!jl_is_function(f) || !jl_is_gf(f))
- return jl_cstr_to_string(const_cast<char*>(""));
+ return NULL;
  sf = jl_get_specialization(f, types);
  }
  if (sf == NULL || sf->linfo == NULL) {
  sf = jl_method_lookup_by_type(jl_gf_mtable(f), types, 0, 0);
  if (sf == jl_bottom_func)
- return jl_cstr_to_string(const_cast<char*>(""));
+ return NULL;
  JL_PRINTF(JL_STDERR,
  "Warning: Returned code may not match what actually runs.\n");
  }
@@ -846,14 +846,23 @@ const jl_value_t *jl_dump_function(jl_function_t *f, jl_tuple_t *types, bool dum
  jl_compile(sf);
  }
  if (sf->fptr == &jl_trampoline) {
- if (!dumpwrapper && sf->linfo->cFunctionObject != NULL)
+ if (!getwrapper && sf->linfo->cFunctionObject != NULL)
  llvmf = (Function*)sf->linfo->cFunctionObject;
  else
  llvmf = (Function*)sf->linfo->functionObject;
  }
  else {
  llvmf = to_function(sf->linfo, false);
  }
+ return llvmf;
+}
+
+extern "C" DLLEXPORT
+const jl_value_t *jl_dump_function(jl_function_t *f, jl_tuple_t *types, bool dumpasm, bool dumpwrapper)
+{
+ void *llvmf = jl_get_llvmf(f,types,dumpwrapper);
+ if (llvmf == NULL)
+ return jl_cstr_to_string(const_cast<char*>(""));
  return jl_dump_llvmf(llvmf,dumpasm);
 }