merge-ll: rename from ll-merge

A long term (but rather minor) pet-peeve of mine was the name
ll-merge.[ch].  I thought it made it harder to realize what stuff was
related to merging when I was working on the merge machinery and trying
to improve it.

Further, back in d1cbe1e6d8 ("hash-ll.h: split out of hash.h to remove
dependency on repository.h", 2023-04-22), we have split the portions of
hash.h that do not depend upon repository.h into a "hash-ll.h" (due to
the recommendation to use "ll" for "low-level" in its name[1], but which
I used as a suffix precisely because of my distaste for "ll-merge").
When we discussed adding additional "*-ll.h" files, a request was made
that we use "ll" consistently as either a prefix or a suffix.  Since it
is already in use as both a prefix and a suffix, the only way to do so
is to rename some files.

Besides my distaste for the ll-merge.[ch] name, let me also note that
the files
  ll-fsmonitor.h, ll-hash.h, ll-merge.h, ll-object-store.h, ll-read-cache.h
would have essentially nothing to do with each other and make no sense
to group.  But giving them the common "ll-" prefix would group them.  Using
"-ll" as a suffix thus seems just much more logical to me.  Rename
ll-merge.[ch] to merge-ll.[ch] to achieve this consistency, and to
ensure we get a more logical grouping of files.

[1] https://lore.kernel.org/git/kl6lsfcu1g8w.fsf@chooglen-macbookpro.roam.corp.google.com/

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/technical/api-merge.txt

@@ -28,9 +28,9 @@ and `diff.c` for examples.
 
 * `struct ll_merge_options`
 
-Check ll-merge.h for details.
+Check merge-ll.h for details.
 
 Low-level (single file) merge
 -----------------------------
 
-Check ll-merge.h for details.
+Check merge-ll.h for details.

Makefile

@@ -1051,7 +1051,6 @@ LIB_OBJS += linear-assignment.o
 LIB_OBJS += list-objects-filter-options.o
 LIB_OBJS += list-objects-filter.o
 LIB_OBJS += list-objects.o
-LIB_OBJS += ll-merge.o
 LIB_OBJS += lockfile.o
 LIB_OBJS += log-tree.o
 LIB_OBJS += ls-refs.o
@@ -1060,6 +1059,7 @@ LIB_OBJS += mailmap.o
 LIB_OBJS += match-trees.o
 LIB_OBJS += mem-pool.o
 LIB_OBJS += merge-blobs.o
+LIB_OBJS += merge-ll.o
 LIB_OBJS += merge-ort.o
 LIB_OBJS += merge-ort-wrappers.o
 LIB_OBJS += merge-recursive.o

apply.c

@@ -21,7 +21,7 @@
 #include "gettext.h"
 #include "hex.h"
 #include "xdiff-interface.h"
-#include "ll-merge.h"
+#include "merge-ll.h"
 #include "lockfile.h"
 #include "name-hash.h"
 #include "object-name.h"

builtin/checkout.c

@@ -13,7 +13,7 @@
 #include "gettext.h"
 #include "hex.h"
 #include "hook.h"
-#include "ll-merge.h"
+#include "merge-ll.h"
 #include "lockfile.h"
 #include "mem-pool.h"
 #include "merge-recursive.h"

convert.c

@@ -15,7 +15,7 @@
 #include "sub-process.h"
 #include "trace.h"
 #include "utf8.h"
-#include "ll-merge.h"
+#include "merge-ll.h"
 #include "wrapper.h"
 
 /*

diff.c

@@ -26,7 +26,7 @@
 #include "submodule.h"
 #include "hashmap.h"
 #include "mem-pool.h"
-#include "ll-merge.h"
+#include "merge-ll.h"
 #include "string-list.h"
 #include "strvec.h"
 #include "graph.h"

merge-blobs.c

@@ -1,7 +1,7 @@
 #include "git-compat-util.h"
 #include "run-command.h"
 #include "xdiff-interface.h"
-#include "ll-merge.h"
+#include "merge-ll.h"
 #include "blob.h"
 #include "merge-blobs.h"
 #include "object-store.h"

merge-ll.c

@@ -10,7 +10,7 @@
 #include "attr.h"
 #include "xdiff-interface.h"
 #include "run-command.h"
-#include "ll-merge.h"
+#include "merge-ll.h"
 #include "quote.h"
 #include "strbuf.h"
 #include "wrapper.h"

merge-ort.c

@@ -30,7 +30,7 @@
 #include "gettext.h"
 #include "hex.h"
 #include "entry.h"
-#include "ll-merge.h"
+#include "merge-ll.h"
 #include "match-trees.h"
 #include "mem-pool.h"
 #include "object-name.h"

merge-recursive.c

@@ -20,7 +20,7 @@
 #include "environment.h"
 #include "gettext.h"
 #include "hex.h"
-#include "ll-merge.h"
+#include "merge-ll.h"
 #include "lockfile.h"
 #include "match-trees.h"
 #include "name-hash.h"

notes-merge.c

@@ -12,7 +12,7 @@
 #include "diffcore.h"
 #include "hex.h"
 #include "xdiff-interface.h"
-#include "ll-merge.h"
+#include "merge-ll.h"
 #include "dir.h"
 #include "notes.h"
 #include "notes-merge.h"

rerere.c

@@ -12,7 +12,7 @@
 #include "xdiff-interface.h"
 #include "dir.h"
 #include "resolve-undo.h"
-#include "ll-merge.h"
+#include "merge-ll.h"
 #include "attr.h"
 #include "path.h"
 #include "pathspec.h"