Avoid unnecessary JS call in _emscripten_next_timer. NFC (#26695)

system/lib/libc/musl/src/signal/setitimer.c

diff --git a/system/lib/libc/musl/src/signal/setitimer.c b/system/lib/libc/musl/src/signal/setitimer.c
index 90f3b4a..3cdb64d 100644
--- a/system/lib/libc/musl/src/signal/setitimer.c
+++ b/system/lib/libc/musl/src/signal/setitimer.c
@@ -90,7 +90,11 @@
 			next_timer = fmin(current_timeout_ms[which], next_timer);
 		}
 	}
-	return next_timer - emscripten_get_now();
+	// Avoid calling emscripten_get_now() unless we need to here.
+	if (next_timer != INFINITY) {
+		next_timer -= emscripten_get_now();
+	}
+	return next_timer;
 }
 #endif
 

test/codesize/test_codesize_hello_dylink_all.json

diff --git a/test/codesize/test_codesize_hello_dylink_all.json b/test/codesize/test_codesize_hello_dylink_all.json
index 9c98c66..e449030 100644
--- a/test/codesize/test_codesize_hello_dylink_all.json
+++ b/test/codesize/test_codesize_hello_dylink_all.json
@@ -1,7 +1,7 @@
 {
   "a.out.js": 244278,
-  "a.out.nodebug.wasm": 577639,
-  "total": 821917,
+  "a.out.nodebug.wasm": 577664,
+  "total": 821942,
   "sent": [
     "IMG_Init",
     "IMG_Load",