enlarge varchar of name to bigger value in the symbol table

Some benchmarks need this space for the function name, because of name mangling.

tools/import-trace/import-symbols.sh

@@ -38,7 +38,7 @@ CREATE TABLE IF NOT EXISTS $TABLE (
 variant_id INT NOT NULL,
 address INT UNSIGNED NOT NULL,
 size INT UNSIGNED NOT NULL,
-name VARCHAR(255) NOT NULL,
+name VARCHAR(2000) NOT NULL,
 PRIMARY KEY (variant_id, address)
 ) ENGINE=MyISAM;
 EOT