valgrind: suppress leaks in dlopen and newer libraries

dlopen sets up some thread-local state that isn't cleaned up by
`dlclose`.  Additionally, now that we're linking against different
versions of libssh2 and OpenSSL, we're seeing different leak signatures.

script/valgrind.supp

@@ -41,6 +41,38 @@
 	...
 }
 
+{
+	ignore-openssl-init-leak
+	Memcheck:Leak
+	...
+	fun:git_openssl_stream_global_init
+	...
+}
+
+{
+	ignore-openssl-legacy-init-leak
+	Memcheck:Leak
+	...
+	fun:OPENSSL_init_ssl__legacy
+	...
+}
+
+{
+	ignore-openssl-malloc-leak
+	Memcheck:Leak
+	...
+	fun:git_openssl_malloc
+	...
+}
+
+{
+	ignore-openssl-realloc-leak
+	Memcheck:Leak
+	...
+	fun:git_openssl_realloc
+	...
+}
+
 {
 	ignore-glibc-getaddrinfo-cache
 	Memcheck:Leak
@@ -64,6 +96,22 @@
 	...
 }
 
+{
+	ignore-libssh2-session-create
+	Memcheck:Leak
+	...
+	fun:_git_ssh_session_create
+	...
+}
+
+{
+	ignore-libssh2-setup-conn
+	Memcheck:Leak
+	...
+	fun:_git_ssh_setup_conn
+	...
+}
+
 {
 	ignore-libssh2-gcrypt-control-leak
 	Memcheck:Leak
@@ -178,3 +226,19 @@
 	obj:*libcrypto.so*
 	...
 }
+
+{
+	ignore-dlopen-leak
+	Memcheck:Leak
+	...
+	fun:dlopen
+	...
+}
+
+{
+	ignore-dlopen-leak
+	Memcheck:Leak
+	...
+	fun:_dlerror_run
+	...
+}