Fix sbrk tracing (#22787)

This effectively reverts #19174

Fixes: #21223

Author: sbc100

test/code_size/hello_wasm_worker_wasm.json

@@ -5,8 +5,8 @@
   "a.js.gz": 455,
   "a.ww.js": 115,
   "a.ww.js.gz": 127,
-  "a.wasm": 1879,
-  "a.wasm.gz": 1066,
-  "total": 3277,
-  "total_gz": 2032
+  "a.wasm": 1881,
+  "a.wasm.gz": 1065,
+  "total": 3279,
+  "total_gz": 2031
 }

test/other/codesize/test_codesize_hello_dylink.size

@@ -1 +1 @@
-9789
+9784

tools/system_libs.py

@@ -1053,7 +1053,6 @@ def get_libcall_files(self):
       filenames=['emscripten_memcpy.c', 'emscripten_memset.c',
                  'emscripten_scan_stack.c',
                  'emscripten_get_heap_size.c',  # needed by malloc
-                 'sbrk.c',  # needed by malloc
                  'emscripten_memmove.c'])
     # Calls to iprintf can be generated during codegen. Ideally we wouldn't
     # compile these with -O2 like we do the rest of compiler-rt since its
@@ -1300,7 +1299,6 @@ def get_files(self):
           'sigaction.c',
           'sigtimedwait.c',
           'wasi-helpers.c',
-          'sbrk.c',
           'system.c',
         ])
 
@@ -1733,7 +1731,9 @@ def get_files(self):
     malloc = utils.path_from_root('system/lib', {
       'dlmalloc': 'dlmalloc.c', 'emmalloc': 'emmalloc.c',
     }[malloc_base])
-    return [malloc]
+    # Include sbrk.c in libc, it uses tracing and libc itself doesn't have a tracing variant.
+    sbrk = utils.path_from_root('system/lib/libc/sbrk.c')
+    return [malloc, sbrk]
 
   def get_cflags(self):
     cflags = super().get_cflags()
@@ -1818,13 +1818,10 @@ class libmimalloc(MTLibrary):
     # mimalloc includes some files at the source level, so exclude them here.
     excludes=['alloc-override.c', 'page-queue.c', 'static.c']
   )
-  src_files += files_in_path(
-    path='system/lib/mimalloc/src/prim',
-    filenames=['prim.c']
-  )
-  src_files += files_in_path(
-    path='system/lib/',
-    filenames=['emmalloc.c'])
+  src_files += [utils.path_from_root('system/lib/mimalloc/src/prim/prim.c')]
+  src_files += [utils.path_from_root('system/lib/emmalloc.c')]
+  # Include sbrk.c in libc, it uses tracing and libc itself doesn't have a tracing variant.
+  src_files += [utils.path_from_root('system/lib/libc/sbrk.c')]
 
   def can_use(self):
     return super().can_use() and settings.MALLOC == 'mimalloc'