ralloc: use rzalloc where it's necessary

No change in behavior. ralloc_size is equivalent to rzalloc_size.
That will change though.

Calls not switched to rzalloc_size:
- ralloc_vasprintf
- glsl_type::name allocation (it's filled with snprintf)
- C++ classes where valgrind didn't show uninitialized values

I switched most of non-glsl stuff to rzalloc without checking whether
it's really needed.

Reviewed-by: Edward O'Callaghan <funfunctor@folklore1984.net>
Tested-by: Edmondo Tommasina <edmondo.tommasina@gmail.com>
Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>

src/compiler/glsl/link_uniform_blocks.cpp

@@ -310,7 +310,7 @@ create_buffer_blocks(void *mem_ctx, struct gl_context *ctx,
    /* Allocate storage to hold all of the information related to uniform
     * blocks that can be queried through the API.
     */
-   struct gl_uniform_block *blocks = ralloc_array(mem_ctx, gl_uniform_block, num_blocks);
+   struct gl_uniform_block *blocks = rzalloc_array(mem_ctx, gl_uniform_block, num_blocks);
    gl_uniform_buffer_variable *variables =
       ralloc_array(blocks, gl_uniform_buffer_variable, num_variables);