Repository: go
Issue: cmd/compile: large type switches that always match the first value are slower in Go 1.22
Labels: NeedsInvestigation,compiler/runtime

### Go version

go version go1.22.0 linux/amd64

### Output of `go env` in your module/workspace:

```shell
GO111MODULE=''
GOARCH='amd64'
GOBIN=''
GOCACHE='/home/dominique/.cache/go-build'
GOENV='/home/dominique/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMODCACHE='/home/dominique/go/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/home/dominique/go'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/usr/local/go'
GOSUMDB='sum.golang.org'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/local/go/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.22.0'
GCCGO='gccgo'
GOAMD64='v1'
AR='ar'
CC='gcc'
CXX='g++'
CGO_ENABLED='1'
GOMOD='/dev/null'
GOWORK=''
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
PKG_CONFIG='pkg-config'
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build1026376215=/tmp/go-build -gno-record-gcc-switches'
```


### What did you do?

The benchmark `BenchmarkDeepValueSameGoRoutine` in package `context` became 2x slower in go 1.22.

Run the following command:
```
go test -v -run=BenchmarkDeepValueSameGoRoutine -bench=BenchmarkDeepValueSameGoRoutine
```

### What did you see happen?

With go 1.21.0, I get the following:
```
goos: linux
goarch: amd64
pkg: context
cpu: AMD Ryzen 9 3950X 16-Core Processor
BenchmarkDeepValueSameGoRoutine
BenchmarkDeepValueSameGoRoutine/depth=10
BenchmarkDeepValueSameGoRoutine/depth=10-16             35302640                33.76 ns/op
BenchmarkDeepValueSameGoRoutine/depth=20
BenchmarkDeepValueSameGoRoutine/depth=20-16             15910783                69.36 ns/op
BenchmarkDeepValueSameGoRoutine/depth=30
BenchmarkDeepValueSameGoRoutine/depth=30-16             11908124                98.36 ns/op
BenchmarkDeepValueSameGoRoutine/depth=50
BenchmarkDeepValueSameGoRoutine/depth=50-16              7204759               164.2 ns/op
BenchmarkDeepValueSameGoRoutine/depth=100
BenchmarkDeepValueSameGoRoutine/depth=100-16             3947766               298.7 ns/op
PASS
ok      context 6.532s
```

With go 1.22.0 I get this:
```
goos: linux
goarch: amd64
pkg: context
cpu: AMD Ryzen 9 3950X 16-Core Processor
BenchmarkDeepValueSameGoRoutine
BenchmarkDeepValueSameGoRoutine/depth=10
BenchmarkDeepValueSameGoRoutine/depth=10-16             19228312                62.40 ns/op
BenchmarkDeepValueSameGoRoutine/depth=20
BenchmarkDeepValueSameGoRoutine/depth=20-16             11805692               102.0 ns/op
BenchmarkDeepValueSameGoRoutine/depth=30
BenchmarkDeepValueSameGoRoutine/depth=30-16              8119362               141.5 ns/op
BenchmarkDeepValueSameGoRoutine/depth=50
BenchmarkDeepValueSameGoRoutine/depth=50-16              5516227               216.1 ns/op
BenchmarkDeepValueSameGoRoutine/depth=100
BenchmarkDeepValueSameGoRoutine/depth=100-16             2936217               412.7 ns/op
PASS
ok      context 6.924s
```

### What did you expect to see?

No performance degradation.