multi-argument operator[] breaks intellisense

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Type: Bug

multi-argument operator[] breaks intellisense. e.g.

template<class T, int N, int M>
struct mat {
    T a[N][M];

    T &operator[](int i, int j) { return a[i][j]; }
};
mat4 f;
    print(f[0, 0]);

causes a red squiggle with description

no operator "[]" matches these operandsC/C++(349)
main.cpp(20, 12): operand types are: mat4 [ int ]
main.cpp(20, 12): built-in operator[](, <ptrdiff_t>) does not match because argument #1 does not match parameter
main.cpp(20, 12): built-in operator[](<ptrdiff_t>, ) does not match because argument #1 does not match parameter

Extension version: 1.23.6
VS Code version: Code 1.98.2 (ddc367ed5c8936efe395cffeec279b04ffd7db78, 2025-03-12T13:32:45.399Z)
OS version: Windows_NT x64 10.0.19045
Modes: Unsupported

System Info

Item	Value
CPUs	12th Gen Intel(R) Core(TM) i9-12900K (24 x 3187)
GPU Status	2d_canvas: enabled canvas_oop_rasterization: enabled_on direct_rendering_display_compositor: disabled_off_ok gpu_compositing: enabled multiple_raster_threads: enabled_on opengl: enabled_on rasterization: enabled raw_draw: disabled_off_ok skia_graphite: disabled_off video_decode: enabled video_encode: enabled vulkan: disabled_off webgl: enabled webgl2: enabled webgpu: enabled webnn: disabled_off
Load (avg)	undefined
Memory (System)	63.75GB (47.06GB free)
Process Argv	--crash-reporter-id 280fe042-c548-46f7-a820-a3a3af7da63e
Screen Reader	no
VM	0%

A/B Experiments

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vscod805cf:30301675
binariesv615:30325510
py29gd2263:31024239
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azure-dev_surveyone:30548225
a9j8j154:30646983
962ge761:30959799
2e7ec940:31000449
pythontbext0:30879054
cppperfnew:31000557
dwnewjupytercf:31046870
nativerepl1:31139838
pythonrstrctxt:31112756
nativeloc1:31192215
iacca1:31171482
5fd0e150:31155592
dwcopilot:31170013
6074i472:31201624
dwoutputs:31242946
customenabled:31248079
hdaa2157:31222309
copilot_t_ci:31222730
850i5325:31264362
968h8231:31262364
jda6j935:31233686
pythoneinst12:31262605
bgcontrol:31262794
fh1c7952:31258891
31787653:31262186
793h1473:31266633
80860236:31264450
49da9784:31264548

Reproduce the issue using the provided C++ mat example and the C/C++ extension in VS Code. Trace how IntelliSense handles a multi-argument operator[] and verify completion and diagnostics for f[0, 0]; done means the expression no longer shows the reported red squiggle or operator mismatch.

Written by the indexing model from the issue text.

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