Build.zig: create: debug_stack_frames_count is uninitialized

[CorruptedVor]

Zig Version

master (07e7cfa)

Steps to Reproduce and Observed Behavior

this is an issue because Build/Step.zig uses it to alloc something

zig/lib/std/Build/Step.zig

Line 224 in 07e7cfa

const addresses = arena.alloc(usize, options.owner.debug_stack_frames_count) catch @panic("OOM");

triggers a valgrind warnings in the test suite:

 74 69/74 Build.Step.Options.decltest.Options...==13996== Conditional jump or move depends on uninitialised value(s)
 75 ==13996==    at 0x10C40CC: math.mul__anon_11976 (math.zig:562)
 76 ==13996==    by 0x112A9EC: mem.Allocator.allocWithSizeAndAlignment__anon_28635 (Allocator.zig:268)
 77 ==13996==    by 0x11D5797: allocAdvancedWithRetAddr (Allocator.zig:257)
 78 ==13996==    by 0x11D5797: mem.Allocator.alloc__anon_121063 (Allocator.zig:181)
 79 ==13996==    by 0x11B3ACD: Build.Step.init (Step.zig:224)
 80 ==13996==    by 0x11AF230: Build.create (Build.zig:290)
 81 ==13996==    by 0x11AC5EC: Build.Step.Options.decltest.Options (Options.zig:555)
 82 ==13996==    by 0x1115E8A: test_runner.mainTerminal (test_runner.zig:218)
 83 ==13996==    by 0x110FE81: test_runner.main (test_runner.zig:66)
 84 ==13996==    by 0x110F61D: callMain (start.zig:618)
 85 ==13996==    by 0x110F61D: callMainWithArgs (start.zig:587)
 86 ==13996==    by 0x110F61D: main (start.zig:602)

additional context: #24833 (comment)

Expected Behavior

debug_stack_frames_count is initialized, not triggering any valgrind warnings in the test suite