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/nir/nir.c

@@ -448,9 +448,10 @@ nir_alu_instr *
 nir_alu_instr_create(nir_shader *shader, nir_op op)
 {
    unsigned num_srcs = nir_op_infos[op].num_inputs;
+   /* TODO: don't use rzalloc */
    nir_alu_instr *instr =
-      ralloc_size(shader,
-                  sizeof(nir_alu_instr) + num_srcs * sizeof(nir_alu_src));
+      rzalloc_size(shader,
+                   sizeof(nir_alu_instr) + num_srcs * sizeof(nir_alu_src));
 
    instr_init(&instr->instr, nir_instr_type_alu);
    instr->op = op;
@@ -486,8 +487,9 @@ nir_intrinsic_instr *
 nir_intrinsic_instr_create(nir_shader *shader, nir_intrinsic_op op)
 {
    unsigned num_srcs = nir_intrinsic_infos[op].num_srcs;
+   /* TODO: don't use rzalloc */
    nir_intrinsic_instr *instr =
-      ralloc_size(shader,
+      rzalloc_size(shader,
                   sizeof(nir_intrinsic_instr) + num_srcs * sizeof(nir_src));
 
    instr_init(&instr->instr, nir_instr_type_intrinsic);