gdb/

Make value allocations more lazy.
	* ada-lang.c (coerce_unspec_val_to_type): Use allocate_value_lazy
	instead of allocate_value and set_value_lazy when possible.
	* dwarf2loc.c (dwarf2_evaluate_loc_desc_full): Use allocate_value_lazy
	instead of allocate_value and set_value_lazy.
	* findvar.c (value_of_register_lazy): Likewise.
	(read_var_value): Remove V preallocation, call just check_typedef in
	advance.  Move allocate_value to LOC_CONST, LOC_LABEL,
	LOC_CONST_BYTES.  Use allocate_value_lazy in LOC_STATIC, LOC_ARG,
	LOC_REF_ARG, LOC_LOCAL, LOC_BLOCK.  Set ADDR instead of
	set_value_address and break in LOC_BLOCK.  Use allocate_value_lazy and
	remove lval_memory set in LOC_REGPARM_ADDR.  Use allocate_value_lazy
	in LOC_UNRESOLVED and LOC_OPTIMIZED_OUT.  Add setting lval_memory at
	the end, remove set_value_lazy there.
	* valarith.c (value_subscripted_rvalue): Use allocate_value_lazy
	instead of allocate_value and set_value_lazy when possible.
	* valops.c (value_fetch_lazy): Do nop for value_optimized_out VAL.
	* value.c (allocate_computed_value): Use allocate_value_lazy instead
	of allocate_value and set_value_lazy.
	(value_from_contents_and_address): Use allocate_value_lazy instead of
	allocate_value and set_value_lazy when possible.

gdb/valops.c

@@ -1104,6 +1104,8 @@ value_fetch_lazy (struct value *val)
     }
   else if (VALUE_LVAL (val) == lval_computed)
     value_computed_funcs (val)->read (val);
+  else if (value_optimized_out (val))
+    /* Keep it optimized out.  */;
   else
     internal_error (__FILE__, __LINE__, _("Unexpected lazy value type."));