Fix linux-sgx build error when libc-wasi is disabled (#2997)

Compilation error was reported when `cmake -DWAMR_BUILD_LIBC_WASI=0`
on linux-sgx platform:
```
core/shared/platform/linux-sgx/sgx_socket.c:8:10:
fatal error: libc_errno.h: No such file or directory
    8 | #include "libc_errno.h"
      |          ^~~~~~~~~~~~~~
```
After fixing, both `cmake -DWAMR_BUILD_LIBC_WASI=1` and
`WAMR_BUILD_LIBC_WASI=0` work good.

core/shared/platform/linux-sgx/sgx_platform.c

@@ -119,6 +119,18 @@ strcpy(char *dest, const char *src)
     return dest;
 }
 
+#if WASM_ENABLE_LIBC_WASI == 0
+bool
+os_is_handle_valid(os_file_handle *handle)
+{
+    assert(handle != NULL);
+
+    return *handle > -1;
+}
+#else
+/* implemented in posix_file.c */
+#endif
+
 void *
 os_mmap(void *hint, size_t size, int prot, int flags, os_file_handle file)
 {

core/shared/platform/linux-sgx/sgx_socket.c

@@ -5,10 +5,11 @@
 
 #include "platform_api_vmcore.h"
 #include "platform_api_extension.h"
-#include "libc_errno.h"
 
 #ifndef SGX_DISABLE_WASI
 
+#include "libc_errno.h"
+
 #define TRACE_OCALL_FAIL() os_printf("ocall %s failed!\n", __FUNCTION__)
 
 /** OCALLs prototypes **/

product-mini/platforms/linux-sgx/CMakeLists.txt

@@ -164,3 +164,15 @@ else()
         OUTPUT_VARIABLE cmdOutput
     )
 endif()
+
+if (WAMR_BUILD_LIBC_WASI EQUAL 1)
+    execute_process(
+        COMMAND bash -c "sed -i -E 's/^WAMR_BUILD_LIBC_WASI = 0/WAMR_BUILD_LIBC_WASI = 1/g' ${CMAKE_CURRENT_SOURCE_DIR}/enclave-sample/Makefile"
+        OUTPUT_VARIABLE cmdOutput
+    )
+else()
+    execute_process(
+        COMMAND bash -c "sed -i -E 's/^WAMR_BUILD_LIBC_WASI = 1/WAMR_BUILD_LIBC_WASI = 0/g' ${CMAKE_CURRENT_SOURCE_DIR}/enclave-sample/Makefile"
+        OUTPUT_VARIABLE cmdOutput
+    )
+endif()

product-mini/platforms/linux-sgx/enclave-sample/Enclave/Enclave.cpp

@@ -510,7 +510,7 @@ handle_cmd_set_log_level(uint64 *args, uint32 argc)
 #endif
 }
 
-#ifndef SGX_DISABLE_WASI
+#if WASM_ENABLE_LIBC_WASI != 0
 static void
 handle_cmd_set_wasi_args(uint64 *args, int32 argc)
 {
@@ -637,7 +637,7 @@ handle_cmd_set_wasi_args(uint64 *args, int32 argc)
 {
     *args = true;
 }
-#endif /* end of SGX_DISABLE_WASI */
+#endif /* end of WASM_ENABLE_LIBC_WASI != 0 */
 
 static void
 handle_cmd_get_version(uint64 *args, uint32 argc)

product-mini/platforms/linux-sgx/enclave-sample/Makefile

@@ -16,6 +16,7 @@ WAMR_BUILD_LIB_RATS = 0
 WAMR_BUILD_GLOBAL_HEAP_POOL = 0
 WAMR_BUILD_GLOBAL_HEAP_SIZE = 10485760
 WAMR_BUILD_STATIC_PGO = 0
+WAMR_BUILD_LIBC_WASI = 1
 
 VMLIB_BUILD_DIR ?= $(CURDIR)/../build
 LIB_RATS_SRC ?= $(VMLIB_BUILD_DIR)/_deps/librats-build
@@ -66,7 +67,9 @@ ifeq ($(WAMR_BUILD_LIB_RATS), 1)
 	App_Include_Paths += -I$(LIB_RATS_INCLUDE_DIR)
 endif
 
-App_C_Flags := $(SGX_COMMON_CFLAGS) -fPIC -Wno-attributes $(App_Include_Paths) -DWASM_ENABLE_STATIC_PGO=$(WAMR_BUILD_STATIC_PGO)
+App_C_Flags := $(SGX_COMMON_CFLAGS) -fPIC -Wno-attributes $(App_Include_Paths) \
+			   -DWASM_ENABLE_STATIC_PGO=$(WAMR_BUILD_STATIC_PGO) \
+			   -DWASM_ENABLE_LIBC_WASI=$(WAMR_BUILD_LIBC_WASI)
 
 # Three configuration modes - Debug, prerelease, release
 #   Debug - Macro DEBUG enabled.
@@ -135,7 +138,13 @@ ifeq ($(WAMR_BUILD_LIB_RATS), 1)
 	Enclave_Include_Paths += -I$(LIB_RATS_INCLUDE_DIR) -I$(SGX_SSL)/include
 endif
 
-Enclave_C_Flags := $(SGX_COMMON_CFLAGS) -nostdinc -fvisibility=hidden -fpie -fstack-protector $(Enclave_Include_Paths) -DWASM_GLOBAL_HEAP_SIZE=$(WAMR_BUILD_GLOBAL_HEAP_SIZE) -DWASM_ENABLE_GLOBAL_HEAP_POOL=$(WAMR_BUILD_GLOBAL_HEAP_POOL) -DWASM_ENABLE_LIB_RATS=$(WAMR_BUILD_LIB_RATS) -DWASM_ENABLE_STATIC_PGO=$(WAMR_BUILD_STATIC_PGO)
+Enclave_C_Flags := $(SGX_COMMON_CFLAGS) -nostdinc -fvisibility=hidden \
+				   -fpie -fstack-protector $(Enclave_Include_Paths) \
+				   -DWASM_GLOBAL_HEAP_SIZE=$(WAMR_BUILD_GLOBAL_HEAP_SIZE) \
+				   -DWASM_ENABLE_GLOBAL_HEAP_POOL=$(WAMR_BUILD_GLOBAL_HEAP_POOL) \
+				   -DWASM_ENABLE_LIB_RATS=$(WAMR_BUILD_LIB_RATS) \
+				   -DWASM_ENABLE_STATIC_PGO=$(WAMR_BUILD_STATIC_PGO) \
+				   -DWASM_ENABLE_LIBC_WASI=$(WAMR_BUILD_LIBC_WASI)
 ifeq ($(SPEC_TEST), 1)
 	Enclave_C_Flags += -DWASM_ENABLE_SPEC_TEST=1
 else

product-mini/platforms/linux-sgx/enclave-sample/Makefile_minimal

@@ -102,7 +102,7 @@ Enclave_Include_Paths := -IEnclave -I$(WAMR_ROOT)/core/iwasm/include \
 Enclave_C_Flags := $(SGX_COMMON_CFLAGS) -nostdinc -fvisibility=hidden -fpie -fstack-protector $(Enclave_Include_Paths)
 
 # disable wasi
-Enclave_C_Flags += -DSGX_DISABLE_WASI
+Enclave_C_Flags += -DWASM_ENABLE_LIBC_WASI=0
 
 ifeq ($(SPEC_TEST), 1)
 	Enclave_C_Flags += -DWASM_ENABLE_SPEC_TEST=1