Move lookup_block_symbol to block.c, rename to block_lookup_symbol.

There is another function, lookup_symbol_aux_block, and
the names lookup_block_symbol and lookup_symbol_aux_block don't
convey any real difference between them.

The difference is that lookup_block_symbol lives in the lower level
block API, and lookup_symbol_aux_block lives in the higher level symtab API.
This patch makes this distinction clear.

gdb/ChangeLog:

	* symtab.c (lookup_block_symbol): Moved to ...
	* block.c (block_lookup_symbol):  ... here and renamed.
	All callers updated.
	* block.h (block_lookup_symbol): Declare.
	* symtab.h (lookup_block_symbol): Delete.

gdb/block.c

@@ -685,3 +685,61 @@ block_iter_match_next (const char *name,
 
   return block_iter_match_step (iterator, name, compare, 0);
 }
+
+/* See block.h.
+
+   Note that if NAME is the demangled form of a C++ symbol, we will fail
+   to find a match during the binary search of the non-encoded names, but
+   for now we don't worry about the slight inefficiency of looking for
+   a match we'll never find, since it will go pretty quick.  Once the
+   binary search terminates, we drop through and do a straight linear
+   search on the symbols.  Each symbol which is marked as being a ObjC/C++
+   symbol (language_cplus or language_objc set) has both the encoded and
+   non-encoded names tested for a match.  */
+
+struct symbol *
+block_lookup_symbol (const struct block *block, const char *name,
+		     const domain_enum domain)
+{
+  struct block_iterator iter;
+  struct symbol *sym;
+
+  if (!BLOCK_FUNCTION (block))
+    {
+      for (sym = block_iter_name_first (block, name, &iter);
+	   sym != NULL;
+	   sym = block_iter_name_next (name, &iter))
+	{
+	  if (symbol_matches_domain (SYMBOL_LANGUAGE (sym),
+				     SYMBOL_DOMAIN (sym), domain))
+	    return sym;
+	}
+      return NULL;
+    }
+  else
+    {
+      /* Note that parameter symbols do not always show up last in the
+	 list; this loop makes sure to take anything else other than
+	 parameter symbols first; it only uses parameter symbols as a
+	 last resort.  Note that this only takes up extra computation
+	 time on a match.  */
+
+      struct symbol *sym_found = NULL;
+
+      for (sym = block_iter_name_first (block, name, &iter);
+	   sym != NULL;
+	   sym = block_iter_name_next (name, &iter))
+	{
+	  if (symbol_matches_domain (SYMBOL_LANGUAGE (sym),
+				     SYMBOL_DOMAIN (sym), domain))
+	    {
+	      sym_found = sym;
+	      if (!SYMBOL_IS_ARGUMENT (sym))
+		{
+		  break;
+		}
+	    }
+	}
+      return (sym_found);	/* Will be NULL if not found.  */
+    }
+}