Issues report and suggestion

[cpunion]

Some issues impacting development progress, and has some potential problems.

Defer implementation

• Defer in loop:
  • Blocks issues llc cannot be verified defer in phi #907, panic: todo: DeferInLoop is not supported - net.(*Resolver).exchange #958
  • Unnecessary overlays:
    • go/parser/resolver.go
    • testing/testing.go
    • following update is diffucult
  • Blocks development progress of debug info for some cases: Compile failed maybe related to defer #802
  • Related issues: Dead loop in cl/blocks.Infos #965

Closure stubs implementation

Issue reference: #983

• Can't get function address from any type
• Blocks reuse of go standard library sources:
  • Some syscall/libc functions implemented by trampolines in yscall/runtime, can be optimized to func calling by llgo instruction
  • Potential reason: Compiles llgo compiler with go 1.23, run failed #942

Patching

• Incorrect unsafe.Sizeof(sync.Mutex{}), it be parsed to a constant of sync.Mutex size by x/tools, not the size of pthread_mutex_t.
• Maybe cause some potential problems, reuse more go runtime sources is better.
  • reflect.Value not fully patched

Overlay

• It can be replaced by patching for better compatible, if defer in loop be resolved, only net/textproto/textproto.go need patching.

/opt/homebrew/Cellar/go/1.24.0/libexec/src/net/textproto/textproto.go:37:2: no required module provides package github.com/goplus/llgo/runtime/internal/clite; to add it:
	go get github.com/goplus/llgo/runtime/internal/clite
cannot build SSA for package github.com/goplus/llgo/runtime/internal/clite
/opt/homebrew/Cellar/go/1.24.0/libexec/src/net/textproto/textproto.go:38:2: no required module provides package github.com/goplus/llgo/runtime/internal/clite/net; to add it:
	go get github.com/goplus/llgo/runtime/internal/clite/net
cannot build SSA for package github.com/goplus/llgo/runtime/internal/clite/net
/opt/homebrew/Cellar/go/1.24.0/libexec/src/net/textproto/textproto.go:39:2: no required module provides package github.com/goplus/llgo/runtime/internal/clite/os; to add it:
	go get github.com/goplus/llgo/runtime/internal/clite/os
cannot build SSA for package github.com/goplus/llgo/runtime/internal/clite/os
/opt/homebrew/Cellar/go/1.24.0/libexec/src/net/textproto/textproto.go:40:2: no required module provides package github.com/goplus/llgo/runtime/internal/runtime; to add it:
	go get github.com/goplus/llgo/runtime/internal/runtime