Convert job list to a dequeue

We never insert elements into the middle of a job list, only move
elements to the top. While that can be done "efficiently" with a list, it
can be done faster with a deque, which also won't thrash the cache when
enumerating over jobs.

This speeds up enumeration in the critical path in
`process_mark_finished_children()`.

src/parser.cpp

@@ -591,7 +591,7 @@ void parser_t::job_promote(job_t *job) {
     assert(loc != my_job_list.end());
 
     // Move the job to the beginning.
-    my_job_list.splice(my_job_list.begin(), my_job_list, loc);
+    std::rotate(my_job_list.begin(), loc, my_job_list.end());
 }
 
 job_t *parser_t::job_get(job_id_t id) {

src/proc.h

@@ -11,7 +11,7 @@
 #include <termios.h>
 #include <unistd.h>
 
-#include <list>
+#include <deque>
 #include <memory>
 #include <vector>
 
@@ -243,7 +243,7 @@ extern bool is_login;
 extern int is_event;
 
 // List of jobs. We sometimes mutate this while iterating - hence it must be a list, not a vector
-typedef std::list<shared_ptr<job_t>> job_list_t;
+typedef std::deque<shared_ptr<job_t>> job_list_t;
 
 bool job_list_is_empty(void);