Tweak GC settings, particularly for org & lsp

These two modes are particularly expensive. This needs more
testing.

core/core.el

@@ -307,14 +307,14 @@ users).")
 ;; Adopt a sneaky garbage collection strategy of waiting until idle time to
 ;; collect; staving off the collector while the user is working.
 (when doom-interactive-mode
-  (setq gc-cons-percentage 0.6)
+  (setq gcmh-idle-delay 5
+        gcmh-high-cons-threshold 16777216  ; 16mb
+        gcmh-verbose doom-debug-mode
+        gc-cons-percentage 0.6)
   (add-transient-hook! 'pre-command-hook (gcmh-mode +1))
   (with-eval-after-load 'gcmh
-    (setq gcmh-idle-delay 10
-          gcmh-high-cons-threshold 16777216
-          gcmh-verbose doom-debug-mode  ; 16mb
-          gc-cons-percentage 0.1)
-    (add-hook 'focus-out-hook #'gcmh-idle-garbage-collect)))
+    (setq gc-cons-percentage 0.1)
+    (add-hook 'focus-out-hook #'gcmh-idle-garbage-collect))
 
 ;; HACK `tty-run-terminal-initialization' is *tremendously* slow for some
 ;;      reason. Disabling it completely could have many side-effects, so we

modules/lang/org/config.el

@@ -462,6 +462,12 @@ relative to `org-directory', unless it is an absolute path."
   ;; Open directory links in dired
   (add-to-list 'org-file-apps '(directory . emacs))
 
+  ;; HACK Org is known to use a lot of unicode symbols (and large org files tend
+  ;;      to be especially memory hungry). Compounded with
+  ;;      `inhibit-compacting-font-caches' being non-nil, org needs more memory
+  ;;      to be performant.
+  (setq-hook! 'org-mode-hook gcmh-high-cons-threshold (* 2 gcmh-high-cons-threshold))
+
   ;; When you create a sparse tree and `org-indent-mode' is enabled, the
   ;; highlighting destroys the invisibility added by `org-indent-mode'.
   ;; Therefore, don't highlight when creating a sparse tree.

modules/tools/lsp/config.el

@@ -91,6 +91,10 @@ This also logs the resolved project root, if found, so we know where we are."
          ;; development builds of Emacs 27 and above
          (or (not (boundp 'read-process-output-max))
              (setq-local read-process-output-max (* 1024 1024)))
+         ;; REVIEW LSP causes a lot of allocations, with or without Emacs 27+'s
+         ;;        native JSON library, so we up the GC threshold to stave off
+         ;;        GC-induced slowdowns/freezes.
+         (setq-local gcmh-high-cons-threshold (* 2 gcmh-high-cons-threshold))
          (prog1 (lsp-mode 1)
            (setq-local lsp-buffer-uri (lsp--buffer-uri))
            ;; Announce what project root we're using, for diagnostic purposes