Panic: subtract with overflow in render.rs

[nical]

CTS test: cts/webgpu/api/validation/encoding/cmds/render/setVertexBuffer/cts.https.html?q=webgpu:api,validation,encoding,cmds,render,setVertexBuffer:offset_and_size_oob:*

Happening here

Backtrace:

10  xul.dll!core::panicking::panic() [panicking.rs:07dca489ac2d933c78d3c5158e3f43beefeb02ce : 144 + 0x7]
     rbx = 0x0000025c0c9fa9c0    rbp = 0x000000a6bde7c3c0
     rsp = 0x000000a6bde7c2d0    r12 = 0x000000a6bde7ca78
     r13 = 0x0000025c7e46e3c8    r14 = 0x000000a6bde7ca78
     r15 = 0x600000010000000e    rip = 0x00007ff987fb6e42
    Found by: call frame info
11  xul.dll!wgpu_core::global::Global::command_encoder_run_render_pass_impl<wgpu_hal::dx12::Api>(wgpu_core::id::Id<enum2$<wgpu_core::id::markers::CommandEncoder> >, wgpu_core::command::BasePassRef<enum2$<wgpu_core::command::draw::RenderCommand> >, ref$<slice2$<enum2$<core::option::Option<wgpu_core::command::render::RenderPassColorAttachment> > > >, enum2$<core::option::Option<ref$<wgpu_core::command::render::RenderPassDepthStencilAttachment> > >, enum2$<core::option::Option<ref$<wgpu_core::command::render::RenderPassTimestampWrites> > >, enum2$<core::option::Option<wgpu_core::id::Id<enum2$<wgpu_core::id::markers::QuerySet> > > >) [render.rs:94c7d956509d4818aa4580c84b48e16a6933627b : 1758 + 0x17]
     rbx = 0x0000025c0c9fa9c0    rbp = 0x000000a6bde7c3c0
     rsp = 0x000000a6bde7c340    r12 = 0x000000a6bde7ca78
     r13 = 0x0000025c7e46e3c8    r14 = 0x000000a6bde7ca78
     r15 = 0x600000010000000e    rip = 0x00007ff985e9d5d7
    Found by: call frame info
12  xul.dll!wgpu_bindings::server::Global::command_encoder_action<wgpu_hal::dx12::Api>(wgpu_core::id::Id<enum2$<wgpu_core::id::markers::CommandEncoder> >, enum2$<wgpu_core::device::trace::Command>, wgpu_bindings::error::ErrorBuffer) [server.rs:94c7d956509d4818aa4580c84b48e16a6933627b : 977 + 0x35]
     rbx = 0x000000a6bde7e630    rsi = 0x600000010000000e
     rdi = 0x0000025c02336200    rbp = 0x000000a6bde7daa0
     rsp = 0x000000a6bde7da20    r12 = 0x0000000000000001
     r13 = 0x000000a6bde7ea00    r14 = 0x0000000000000000
     r15 = 0x0000025c0f8334c0    rip = 0x00007ff985ef9c15
    Found by: call frame info

[andyleiserson]

Fixed in #7911.