cmd/compile: panic during merge conditional branches

[gopherbot]

#!watchflakes
default <- pkg == "golang.org/x/tools/gopls/internal/test/integration/misc" && test == "" && goarch == "arm" && goos == "linux"

Issue created automatically to collect these failures.

Example (log):

FAIL	golang.org/x/tools/gopls/internal/test/integration/misc [build failed]
# golang.org/x/tools/gopls/internal/test/integration/misc [golang.org/x/tools/gopls/internal/test/integration/misc.test]
internal/test/integration/misc/rename_test.go:190:2: internal compiler error: 'TestRenamePackageWithConflicts.func1': panic during merge conditional branches while compiling TestRenamePackageWithConflicts.func1:

runtime error: invalid memory address or nil pointer dereference

goroutine 66 [running]:
cmd/compile/internal/ssa.Compile.func1()
	cmd/compile/internal/ssa/compile.go:49 +0x7c
panic({0x14cc494, 0x1550a60})
...
cmd/compile/internal/ssa.Compile(0x9508008)
	cmd/compile/internal/ssa/compile.go:97 +0xe70
cmd/compile/internal/ssagen.buildssa(0x6cb03c8, 0x1, 0x0)
	cmd/compile/internal/ssagen/ssa.go:595 +0x3004
cmd/compile/internal/ssagen.Compile(0x6cb03c8, 0x1, 0x0)
	cmd/compile/internal/ssagen/pgen.go:304 +0x88
cmd/compile/internal/gc.compileFunctions.func2()
	cmd/compile/internal/gc/compile.go:177 +0xa0
created by cmd/compile/internal/gc.compileFunctions in goroutine 1
	cmd/compile/internal/gc/compile.go:163 +0xc4

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
default <- pkg == "golang.org/x/tools/gopls/internal/test/integration/misc" && test == ""

2026-03-12 03:16 x_tools-gotip-linux-arm tools@24a8e95f go@26d5e160 x/tools/gopls/internal/test/integration/misc (log)

FAIL	golang.org/x/tools/gopls/internal/test/integration/misc [build failed]
# golang.org/x/tools/gopls/internal/test/integration/misc [golang.org/x/tools/gopls/internal/test/integration/misc.test]
internal/test/integration/misc/rename_test.go:190:2: internal compiler error: 'TestRenamePackageWithConflicts.func1': panic during merge conditional branches while compiling TestRenamePackageWithConflicts.func1:

runtime error: invalid memory address or nil pointer dereference

goroutine 66 [running]:
cmd/compile/internal/ssa.Compile.func1()
	cmd/compile/internal/ssa/compile.go:49 +0x7c
panic({0x14cc494, 0x1550a60})
...
cmd/compile/internal/ssa.Compile(0x9508008)
	cmd/compile/internal/ssa/compile.go:97 +0xe70
cmd/compile/internal/ssagen.buildssa(0x6cb03c8, 0x1, 0x0)
	cmd/compile/internal/ssagen/ssa.go:595 +0x3004
cmd/compile/internal/ssagen.Compile(0x6cb03c8, 0x1, 0x0)
	cmd/compile/internal/ssagen/pgen.go:304 +0x88
cmd/compile/internal/gc.compileFunctions.func2()
	cmd/compile/internal/gc/compile.go:177 +0xa0
created by cmd/compile/internal/gc.compileFunctions in goroutine 1
	cmd/compile/internal/gc/compile.go:163 +0xc4

— watchflakes

[cherrymui]

There was a region of commits that the linux-arm builder is bad. This falls into that region. Probably fixed now.