[console] List commands alphabetically by name in normal mode

This change updates the `help` console command to list the available
commands alphabetically, but only when we're not panicking. This makes
`help`'s helping more helpful.

lib/console/console.c

@@ -785,10 +785,33 @@ console_cmd_func console_get_command_handler(const char *commandstr) {
         return NULL;
 }
 
+// Compare alphabetically by name.
+static int compare_cmds(const void *cmd1, const void *cmd2) {
+    return strcmp(((const console_cmd_block *)cmd1)->name,
+                  ((const console_cmd_block *)cmd2)->name);
+}
+
 static int cmd_help_impl(uint8_t availability_mask) {
     printf("command list by block:\n");
 
-    for (const console_cmd_block *block = &__start_commands; block != &__stop_commands; block++) {
+    // If we're not panicking and are free to allocate memory, sort the commands
+    // alphabetically before printing.
+    const console_cmd_block *start = &__start_commands;
+    const console_cmd_block *end = &__stop_commands;
+    console_cmd_block *sorted = NULL;
+    if ((availability_mask & CMD_AVAIL_PANIC) == 0) {
+        size_t num_cmds = end - start;
+        size_t size_bytes = num_cmds * sizeof(console_cmd_block);
+        sorted = (console_cmd_block *) malloc(size_bytes);
+        if (sorted) {
+            memcpy(sorted, start, size_bytes);
+            qsort(sorted, num_cmds, sizeof(console_cmd_block), compare_cmds);
+            start = sorted;
+            end = sorted + num_cmds;
+        }
+    }
+
+    for (const console_cmd_block *block = start; block != end; block++) {
         const console_cmd *curr_cmd = block->list;
         printf("  [%s]\n", block->name);
         for (size_t i = 0; i < block->count; i++) {
@@ -801,6 +824,9 @@ static int cmd_help_impl(uint8_t availability_mask) {
         }
     }
 
+    if (sorted) {
+        free(sorted);
+    }
     return 0;
 }