Convert block_static_block and block_global_block to methods

This converts block_static_block and block_global_block to be methods.
This was mostly written by script.  It was simpler to convert them at
the same time because they're often used near each other.

gdb/ada-lang.c

@@ -13798,7 +13798,7 @@ public:
     sym = ada_lookup_symbol (name,
 			     (block == nullptr
 			      ? nullptr
-			      : block_static_block (block)),
+			      : block->static_block ()),
 			     domain);
     if (sym.symbol != NULL)
       return sym;