Same here. I removed TSRMLS_DC from apc_copy_zval argument list (apc_compile.c/h) and apc_cache.c compiled fine.

Compiling php_apc.c also in php_apc.c fails:
/root/apc-cvs-20050317/php_apc.c:99: error: parse error before "zend_apc_globals"
/root/apc-cvs-20050317/php_apc.c:99: error: initializer element is not constant
/root/apc-cvs-20050317/php_apc.c:99: error: (near initialization for `ini_entries[0].mh_arg1')
/root/apc-cvs-20050317/php_apc.c:99: error: initializer element is not constant
/root/apc-cvs-20050317/php_apc.c:99: error: (near initialization for `ini_entries[0]')
/root/apc-cvs-20050317/php_apc.c:100: error: parse error before "zend_apc_globals"
...

I was not able to find a way to fix this (don't know anything about ZTS or PHP extensions).

PS. There's also warning about some value being redefined: /root/apc-cvs-20050317/apc_sem.c:38:1: warning: "HAVE_SEMUN" redefined

compiled with changes:
cvs diff
? .deps
? .libs
? Makefile
? Makefile.fragments
? Makefile.global
? Makefile.objects
? acinclude.m4
? aclocal.m4
? apc.la
? apc.lo
? apc_cache.lo
? apc_compile.lo
? apc_debug.lo
? apc_fcntl.lo
? apc_main.lo
? apc_mmap.lo
? apc_optimizer.lo
? apc_pair.lo
? apc_sem.lo
? apc_shm.lo
? apc_sma.lo
? apc_stack.lo
? apc_zend.lo
? autom4te.cache
? build
? config.guess
? config.h
? config.h.in
? config.log
? config.nice
? config.status
? config.sub
? configure
? configure.in
? include
? install-sh
? libtool
? ltmain.sh
? missing
? mkinstalldirs
? modules
? php_apc.lo
cvs diff: Diffing .
Index: apc_cache.c
===================================================================
RCS file: /repository/pecl/apc/apc_cache.c,v
retrieving revision 3.76
diff -r3.76 apc_cache.c
638c638
< apc_cache_entry_t* apc_cache_make_user_entry(const char* info, const zval* val, const unsigned int ttl)
---
> apc_cache_entry_t* apc_cache_make_user_entry(const char* info, const zval* val, const unsigned int ttl TSRMLS_DC)
650c650
<     entry->data.user.val = apc_copy_zval(NULL, val, apc_sma_malloc, apc_sma_free);
---
>     entry->data.user.val = apc_copy_zval(NULL, val, apc_sma_malloc, apc_sma_free TSRMLS_CC);
Index: apc_cache.h
===================================================================
RCS file: /repository/pecl/apc/apc_cache.h,v
retrieving revision 3.23
diff -r3.23 apc_cache.h
193c193
< extern apc_cache_entry_t* apc_cache_make_user_entry(const char* info, const zval *val, const unsigned int ttl);
---
> extern apc_cache_entry_t* apc_cache_make_user_entry(const char* info, const zval *val, const unsigned int ttl TSRMLS_DC);
Index: php_apc.c
===================================================================
RCS file: /repository/pecl/apc/php_apc.c,v
retrieving revision 3.41
diff -r3.41 php_apc.c
348c348
<     if (!(entry = apc_cache_make_user_entry(strkey, val, ttl))) {
---
>     if (!(entry = apc_cache_make_user_entry(strkey, val, ttl TSRMLS_CC))) {
450c450
< static void _apc_define_constants(zval *constants, zend_bool case_sensitive) {
---
> static void _apc_define_constants(zval *constants, zend_bool case_sensitive TSRMLS_DC) {
504c504
<     _apc_define_constants(constants, case_sensitive);
---
>     _apc_define_constants(constants, case_sensitive TSRMLS_CC);
537c537
<         _apc_define_constants(entry->data.user.val, case_sensitive);
---
>         _apc_define_constants(entry->data.user.val, case_sensitive TSRMLS_CC);

This should be fixed in CVS now