Export jl_alloc_array_nd, re-add and export convenience wrappers (#52248)

This is used in an example here in the docs
https://docs.julialang.org/en/v1.11-dev/manual/embedding/#Multidimensional-Arrays
and needed to adapt to the removed `jl_alloc_array_2d` (#51319).

Author: benlorenz

src/array.c

@@ -167,6 +167,18 @@ JL_DLLEXPORT jl_array_t *jl_alloc_array_1d(jl_value_t *atype, size_t nr)
     return new_array(atype, 1, &nr);
 }
 
+JL_DLLEXPORT jl_array_t *jl_alloc_array_2d(jl_value_t *atype, size_t nr, size_t nc)
+{
+    size_t dims[2] = {nr, nc};
+    return new_array(atype, 2, &dims[0]);
+}
+
+JL_DLLEXPORT jl_array_t *jl_alloc_array_3d(jl_value_t *atype, size_t nr, size_t nc, size_t z)
+{
+    size_t dims[3] = {nr, nc, z};
+    return new_array(atype, 3, &dims[0]);
+}
+
 JL_DLLEXPORT jl_array_t *jl_alloc_array_nd(jl_value_t *atype, size_t *dims, size_t ndims)
 {
     return new_array(atype, ndims, dims);

src/jl_exported_funcs.inc

@@ -6,6 +6,9 @@
     XX(jl_adopt_thread) \
     XX(jl_alignment) \
     XX(jl_alloc_array_1d) \
+    XX(jl_alloc_array_2d) \
+    XX(jl_alloc_array_3d) \
+    XX(jl_alloc_array_nd) \
     XX(jl_alloc_string) \
     XX(jl_alloc_svec) \
     XX(jl_alloc_svec_uninit) \

src/julia.h

@@ -1828,6 +1828,9 @@ JL_DLLEXPORT jl_array_t *jl_ptr_to_array(jl_value_t *atype, void *data,
                                          jl_value_t *dims, int own_buffer);
 
 JL_DLLEXPORT jl_array_t *jl_alloc_array_1d(jl_value_t *atype, size_t nr);
+JL_DLLEXPORT jl_array_t *jl_alloc_array_2d(jl_value_t *atype, size_t nr, size_t nc);
+JL_DLLEXPORT jl_array_t *jl_alloc_array_3d(jl_value_t *atype, size_t nr, size_t nc, size_t z);
+JL_DLLEXPORT jl_array_t *jl_alloc_array_nd(jl_value_t *atype, size_t *dims, size_t ndims);
 JL_DLLEXPORT jl_array_t *jl_pchar_to_array(const char *str, size_t len);
 JL_DLLEXPORT jl_value_t *jl_pchar_to_string(const char *str, size_t len);
 JL_DLLEXPORT jl_value_t *jl_cstr_to_string(const char *str);