Fix compilation, add a check for no slow usages of grpc_slice_malloc

include/grpc/slice.h

@@ -128,7 +128,7 @@ GPRAPI grpc_slice grpc_slice_split_tail(grpc_slice *s, size_t split);
  * refcounts (grpc_slice_split_tail_maybe_ref(..., true) is equivalent to
  * grpc_slice_split_tail(...)) */
 GPRAPI grpc_slice grpc_slice_split_tail_maybe_ref(grpc_slice *s, size_t split,
-                                                  bool inc_refs);
+                                                  int inc_refs);
 
 /* Splits s into two: modifies s to be s[split:s.length], and returns a new
    slice, sharing a refcount with s, that contains s[0:split].

src/core/lib/slice/slice.c

@@ -313,7 +313,7 @@ grpc_slice grpc_slice_sub(grpc_slice source, size_t begin, size_t end) {
 }
 
 grpc_slice grpc_slice_split_tail_maybe_ref(grpc_slice *source, size_t split,
-                                           bool incref) {
+                                           int incref) {
   grpc_slice tail;
 
   if (source->refcount == NULL) {

tools/run_tests/sanity/core_banned_functions.py

@@ -50,6 +50,7 @@ BANNED_EXCEPT = {
     'grpc_os_error(': ['src/core/lib/iomgr/error.c'],
     'grpc_wsa_error(': ['src/core/lib/iomgr/error.c'],
     'grpc_log_if_error(': ['src/core/lib/iomgr/error.c'],
+    'grpc_slice_malloc(': ['src/core/lib/slice/slice.c'],
 }
 
 errors = 0