remove .size from startup.s, so linker.ld doesn't need gap-bridge symbols

targets/linker.ld

@@ -46,19 +46,20 @@ SECTIONS {
 
         KEEP (*(".text.startup"))
 
-        . = ALIGN(4096);
-        _wamr_aot_start = .;
-        *(".text.wamr_aot")
-        _wamr_aot_end = .;
-
-        . = ALIGN(4096);
-        _wamr_mmap_start = .;
-        *(".text.wamr_mmap")
-        _wamr_mmap_end = .;
-
         /* .wamr_aot and .wamr_mmap have to be placed before .text,
         * otherwise they'll be caught by the wildcard */
+
+        /* _wamr_aot_start = .; */
+        *(".text.wamr_aot")
+        /* _wamr_aot_end = .; */
+
+        /* _wamr_mmap_start = .; */
+        *(".text.wamr_mmap")
+        /* _wamr_mmap_end = .; */
+
+        /* _text_start = .; */
         *(".text*")
+        /* _text_end = .; */
 
         *(".rodata*")
     }