Intellisense doesn't work with C# 9's target-typed new expressions

[JasonWei512]

Issue Description

Intellisense doens't work when using C# 9's target-typed new expressions.

Steps to Reproduce

Intellisense works in VSCode if you use the traditional new expressions:

But if you use C# 9's target-typed new expressions, intellisense doesn't work:

Expected Behavior

Intellisense should work, like in Visual Studio:

Actual Behavior

Intellisense doesn't work when using target-typed new expressions.

Logs

OmniSharp log

Post the output from Output-->OmniSharp log here

C# log

Post the output from Output-->C# here

Environment information

VSCode version: 1.61.0
C# Extension: 1.23.15

Dotnet Information

.NET SDK (��ӳ�κ� global.json): Version: 6.0.100-rc.1.21463.6 Commit: e627d556a1

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OS Name: Windows
OS Version: 10.0.22000
OS Platform: Windows
RID: win10-x64
Base Path: C:\Program Files\dotnet\sdk\6.0.100-rc.1.21463.6\

Host (useful for support):
Version: 6.0.0-rc.1.21451.13
Commit: d7619cd4b1

.NET SDKs installed:
5.0.401 [C:\Program Files\dotnet\sdk]
6.0.100-rc.1.21463.6 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
Microsoft.AspNetCore.App 3.1.19 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 5.0.10 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 6.0.0-rc.1.21452.15 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.NETCore.App 3.1.19 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 5.0.10 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 6.0.0-rc.1.21451.13 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.WindowsDesktop.App 3.1.19 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 5.0.10 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 6.0.0-rc.1.21451.3 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

To install additional .NET runtimes or SDKs:
https://aka.ms/dotnet-download

Visual Studio Code Extensions

Extension	Author	Version
auto-using	Fudge	0.7.15
back-n-forth	nick-rudenko	3.1.1
bing-search	kameshkotwani	0.0.1
copilot	GitHub	1.5.2993
cpptools	ms-vscode	1.6.0
csharp	ms-dotnettools	1.23.15
csharpextensions	jchannon	1.3.1
docomment	k--kato	0.1.20
dotnet-interactive-vscode	ms-dotnettools	1.0.2506040
gitlens	eamodio	11.6.1
html-preview-vscode	george-alisson	0.2.5
json-tools	eriklynd	1.0.2
jupyter	ms-toolsai	2021.9.1001312534
jupyter-keymap	ms-toolsai	1.0.0
jupyter-renderers	ms-toolsai	1.0.3
markdown-all-in-one	yzhang	3.4.0
powershell	ms-vscode	2021.10.0
python	ms-python	2021.10.1317843341
remote-containers	ms-vscode-remote	0.202.1
remote-ssh	ms-vscode-remote	0.65.8
remote-ssh-edit	ms-vscode-remote	0.65.8
remote-wsl	ms-vscode-remote	0.58.2
rust-analyzer	matklad	0.2.768
todo-tree	Gruntfuggly	0.0.214
v2ex-playground	chaselen	1.4.5
vetur	octref	0.34.1
vscode-colorize	kamikillerto	0.11.1
vscode-counter	uctakeoff	2.3.0
vscode-hexdump	slevesque	1.8.1
vscode-icons	vscode-icons-team	11.6.0
vscode-language-pack-zh-hans	MS-CEINTL	1.61.3
vscode-pylance	ms-python	2021.10.0
vscode-remote-extensionpack	ms-vscode-remote	0.21.0
vscode-wordcount-cjk	holmescn	1.3.1
vscodeintellicode	VisualStudioExptTeam	1.2.14
vue	jcbuisson	0.1.5
xml	DotJoshJohnson	2.5.1

[nohwnd]

Thanks for reporting this, this needs some work on the omnisharp-roslyn server to work correctly.