nir: fix 5 warnings

Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/3970>

src/compiler/nir/nir_lower_clip.c

@@ -466,7 +466,7 @@ bool
 nir_lower_clip_fs(nir_shader *shader, unsigned ucp_enables,
                   bool use_clipdist_array)
 {
-   nir_variable *in[2];
+   nir_variable *in[2] = {0};
    int maxloc = -1;
 
    if (!ucp_enables)

src/compiler/nir_types.cpp

@@ -657,7 +657,7 @@ glsl_get_natural_size_align_bytes(const struct glsl_type *type,
    }
 
    case GLSL_TYPE_ARRAY: {
-      unsigned elem_size, elem_align;
+      unsigned elem_size = 0, elem_align = 0;
       glsl_get_natural_size_align_bytes(type->fields.array,
                                         &elem_size, &elem_align);
       *align = elem_align;

src/compiler/spirv/vtn_glsl450.c

@@ -121,7 +121,7 @@ build_mat_subdet(struct nir_builder *b, struct vtn_ssa_value *src,
       return nir_channel(b, src->elems[1 - col]->def, 1 - row);
    } else {
       /* Swizzle to get all but the specified row */
-      unsigned swiz[3];
+      unsigned swiz[NIR_MAX_VEC_COMPONENTS] = {0};
       for (unsigned j = 0; j < 3; j++)
          swiz[j] = j + (j >= row);
 

src/gallium/auxiliary/nir/tgsi_to_nir.c

@@ -2302,7 +2302,7 @@ static void
 ttn_parse_tgsi(struct ttn_compile *c, const void *tgsi_tokens)
 {
    struct tgsi_parse_context parser;
-   int ret;
+   ASSERTED int ret;
 
    ret = tgsi_parse_init(&parser, tgsi_tokens);
    assert(ret == TGSI_PARSE_OK);

src/mesa/state_tracker/st_nir_lower_builtin.c

@@ -204,7 +204,7 @@ lower_builtin_block(lower_builtin_state *state, nir_block *block)
       nir_ssa_def *def = nir_load_var(b, new_var);
 
       /* swizzle the result: */
-      unsigned swiz[4];
+      unsigned swiz[NIR_MAX_VEC_COMPONENTS] = {0};
       for (unsigned i = 0; i < 4; i++) {
          swiz[i] = GET_SWZ(element->swizzle, i);
          assert(swiz[i] <= SWIZZLE_W);