x/tools/gopls: ChangeSignature: OOB panic in inline.updateCalleeParams (mismatched syntactic/semantic params)

[adonovan]

#!stacks
"goPanicIndex" && "updateCalleeParams.func1"

Issue created by stacks.

func updateCalleeParams(calleeDecl *ast.FuncDecl, params []*parameter) {
...
	filterParams := func(field *ast.Field) {
...
			for _, id := range field.Names {
				if pinfo := params[paramIdx]; pinfo != nil { <--- panic

(Similar to #73912, but a distinct crash.)

This stack uzSaXQ was reported by telemetry:

• crash/crash
• runtime.gopanic:+69
• runtime.goPanicIndex:+2
• golang.org/x/tools/internal/refactor/inline.updateCalleeParams.func1:=2202
• golang.org/x/tools/internal/refactor/inline.updateCalleeParams:+54
• golang.org/x/tools/internal/refactor/inline.(*state).inlineCall:+428
• golang.org/x/tools/internal/refactor/inline.(*state).inline:+17
• golang.org/x/tools/internal/refactor/inline.Inline:+13
• golang.org/x/tools/gopls/internal/golang.inlineAllCalls:+171
• golang.org/x/tools/gopls/internal/golang.rewriteCalls:+118
• golang.org/x/tools/gopls/internal/golang.ChangeSignature:+142
• golang.org/x/tools/gopls/internal/server.(*commandHandler).ChangeSignature.func1:+15
• golang.org/x/tools/gopls/internal/server.(*commandHandler).run.func2:+3
• golang.org/x/tools/gopls/internal/server.(*commandHandler).run:+81
• golang.org/x/tools/gopls/internal/server.(*commandHandler).ChangeSignature:+2
• golang.org/x/tools/gopls/internal/protocol/command.Dispatch:+45
• golang.org/x/tools/gopls/internal/server.(*server).ResolveCodeAction:+21
• golang.org/x/tools/gopls/internal/protocol.serverDispatch:+46

golang.org/x/tools/gopls@v0.18.1 go1.24.3 darwin/arm64 other,vscode (1)