internal/cabi: support target esp32c3

internal/crosscompile/crosscompile.go

@@ -34,6 +34,7 @@ type Export struct {
 	ClangRoot    string   // Root directory of custom clang installation
 	ClangBinPath string   // Path to clang binary directory
 
+	TargetABI    string // RISC-V Target ABI (e.g., "lp64", "lp64d")
 	BinaryFormat string // Binary format (e.g., "elf", "esp", "uf2")
 	FormatDetail string // For uf2, it's uf2FamilyID
 	Emulator     string // Emulator command template (e.g., "qemu-system-arm -M {} -kernel {}")
@@ -453,6 +454,7 @@ func UseTarget(targetName string) (export Export, err error) {
 	export.GOOS = config.GOOS
 	export.GOARCH = config.GOARCH
 	export.ExtraFiles = config.ExtraFiles
+	export.TargetABI = config.TargetABI
 	export.BinaryFormat = config.BinaryFormat
 	export.FormatDetail = config.FormatDetail()
 	export.Emulator = config.Emulator