Let's make C-M-w in isearch yank symbol, not delete character

[Daniel Colascione]

Right now, C-w in search-mode yanks a word from the buffer and globs it 
onto the end of the search result. I usually want to search for symbols, 
not words, so I end up pressing C-w multiple times. C-M-w would be the 
natural keybinding for yanking a symbol instead of a word, but it's 
already taken by isearch-del-char. How about moving isearch-del-char 
somewhere else, like C-d, and making C-M-w yank a whole symbol?