treewide: remove unnecessary includes of cache.h

The last several commits were geared at replacing the include of cache.h
in strbuf.c with an include of git-compat-util.h.  Unfortunately, I had
to drop a patch moving some functions from cache.h to object-name.h, due
to excessive conflicts with other in-flight topics.

However, even without that patch, the series of patches so far allows us
to modify a number of C files to replace an include of cache.h with
git-compat-util.h.  Do that to reduce our dependencies.

(If we could have kept our object-name.h patch in this series, it would
have also let us reduce the includes in checkout.c and fmt-merge-msg.c
in addition to strbuf.c).

Just to ensure that nothing else was bringing in cache.h, all of the
affected files have been checked to ensure that
    gcc -E -I. $SOURCE_FILE | grep '"cache.h"'
found no hits and that
    make DEVELOPER=1 ${OBJECT_FILE_FOR_SOURCE_FILE}
successfully compiles without warnings.

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

compat/terminal.c

@@ -1,4 +1,4 @@
-#include "cache.h"
+#include "git-compat-util.h"
 #include "compat/terminal.h"
 #include "gettext.h"
 #include "sigchain.h"

gpg-interface.c

@@ -1,4 +1,4 @@
-#include "cache.h"
+#include "git-compat-util.h"
 #include "commit.h"
 #include "config.h"
 #include "gettext.h"

lockfile.c

@@ -2,7 +2,7 @@
  * Copyright (c) 2005, Junio C Hamano
  */
 
-#include "cache.h"
+#include "git-compat-util.h"
 #include "abspath.h"
 #include "gettext.h"
 #include "lockfile.h"

parse-options.c

@@ -1,7 +1,6 @@
 #include "git-compat-util.h"
 #include "parse-options.h"
 #include "abspath.h"
-#include "cache.h"
 #include "config.h"
 #include "commit.h"
 #include "color.h"

t/helper/test-delta.c

@@ -11,7 +11,6 @@
 #include "test-tool.h"
 #include "git-compat-util.h"
 #include "delta.h"
-#include "cache.h"
 #include "wrapper.h"
 
 static const char usage_str[] =

t/helper/test-trace2.c

@@ -1,9 +1,9 @@
 #include "test-tool.h"
-#include "cache.h"
 #include "strvec.h"
 #include "run-command.h"
 #include "exec-cmd.h"
 #include "config.h"
+#include "trace2.h"
 
 typedef int(fn_unit_test)(int argc, const char **argv);
 

tempfile.c

@@ -42,7 +42,8 @@
  * file created by its parent.
  */
 
-#include "cache.h"
+#include "git-compat-util.h"
+#include "path.h"
 #include "tempfile.h"
 #include "sigchain.h"
 #include "wrapper.h"

trace2/tr2_cfg.c

@@ -1,5 +1,7 @@
-#include "cache.h"
+#include "git-compat-util.h"
 #include "config.h"
+#include "strbuf.h"
+#include "trace2.h"
 #include "trace2/tr2_cfg.h"
 #include "trace2/tr2_sysenv.h"
 

trace2/tr2_cmd_name.c

@@ -1,4 +1,5 @@
-#include "cache.h"
+#include "git-compat-util.h"
+#include "strbuf.h"
 #include "trace2/tr2_cmd_name.h"
 
 #define TR2_ENVVAR_PARENT_NAME "GIT_TRACE2_PARENT_NAME"

trace2/tr2_dst.c

@@ -1,6 +1,7 @@
-#include "cache.h"
+#include "git-compat-util.h"
 #include "abspath.h"
 #include "sigchain.h"
+#include "strbuf.h"
 #include "trace2/tr2_dst.h"
 #include "trace2/tr2_sid.h"
 #include "trace2/tr2_sysenv.h"

trace2/tr2_sid.c

@@ -1,5 +1,6 @@
-#include "cache.h"
+#include "git-compat-util.h"
 #include "hex.h"
+#include "strbuf.h"
 #include "trace2/tr2_tbuf.h"
 #include "trace2/tr2_sid.h"
 

usage.c

@@ -3,8 +3,9 @@
  *
  * Copyright (C) Linus Torvalds, 2005
  */
-#include "cache.h"
+#include "git-compat-util.h"
 #include "gettext.h"
+#include "trace2.h"
 #include "wrapper.h"
 
 static void vreportf(const char *prefix, const char *err, va_list params)