Functions: use static names for multi-functions

Previously, the function names were stored in `std::string` and were often
created dynamically (especially when the function just output a constant).
This resulted in a lot of overhead.

Now the function name is just a `const char *` that should be statically
allocated. This is good enough for the majority of cases. If a multi-function
needs a more dynamic name, it can override the `MultiFunction::debug_name`
method.

In my test file with >400,000 simple math nodes, the execution time improves from
3s to 1s.

1 files changed, 1 insertions, 1 deletions

diff --git a/source/blender/functions/FN_multi_function_procedure_executor.hh b/source/blender/functions/FN_multi_function_procedure_executor.hh
index 9c8b59739b8..b12e3a91210 100644
--- a/source/blender/functions/FN_multi_function_procedure_executor.hh
+++ b/source/blender/functions/FN_multi_function_procedure_executor.hh
@@ -31,7 +31,7 @@ class MFProcedureExecutor : public MultiFunction {
   const MFProcedure &procedure_;
 
  public:
-  MFProcedureExecutor(std::string name, const MFProcedure &procedure);
+  MFProcedureExecutor(const MFProcedure &procedure);
 
   void call(IndexMask mask, MFParams params, MFContext context) const override;
 };