support elfloader for shared object and relocatable object

1. elfloader for shared object
example: TencentOS-tiny\examples\elfloader_shared_object
keil: TencentOS-tiny\board\TencentOS_tiny_EVB_MX_Plus\KEIL\elfloader_shared_object

2. elfloader for relocatable object:
example: TencentOS-tiny\examples\elfloader_relocatable_object
keil: TencentOS-tiny\board\TencentOS_tiny_EVB_MX_Plus\KEIL\elfloader_relocatable_object

3. TODO:
- add icache/dcache flush when module is loaded
- support more relocation type in elfloader_arch_relocate

components/elfloader/common/include/tos_elfloader_err.h

@@ -0,0 +1,38 @@
+/*----------------------------------------------------------------------------
+ * Tencent is pleased to support the open source community by making TencentOS
+ * available.
+ *
+ * Copyright (C) 2019 THL A29 Limited, a Tencent company. All rights reserved.
+ * If you have downloaded a copy of the TencentOS binary from Tencent, please
+ * note that the TencentOS binary is licensed under the BSD 3-Clause License.
+ *
+ * If you have downloaded a copy of the TencentOS source code from Tencent,
+ * please note that TencentOS source code is licensed under the BSD 3-Clause
+ * License, except for the third-party components listed below which are
+ * subject to different license terms. Your integration of TencentOS into your
+ * own projects may require compliance with the BSD 3-Clause License, as well
+ * as the other licenses applicable to the third-party components included
+ * within TencentOS.
+ *---------------------------------------------------------------------------*/
+
+#ifndef _TOS_ELFLOADER_ERR_H_
+#define  _TOS_ELFLOADER_ERR_H_
+
+typedef enum elfloader_err_en {
+    ELFLOADER_ERR_NONE,
+    ELFLOADER_ERR_HEADER_INVALID,
+    ELFLOADER_ERR_TYPE_INVALID,
+    ELFLOADER_ERR_NO_DYN,
+    ELFLOADER_ERR_NO_SYMTAB,
+    ELFLOADER_ERR_NO_STRTAB,
+    ELFLOADER_ERR_NO_TEXT,
+    ELFLOADER_ERR_NO_LOAD_SEGMENTS,
+    ELFLOADER_ERR_FD_READ_FAILED,
+    ELFLOADER_ERR_SECTION_NOT_FOUND,
+    ELFLOADER_ERR_SYM_NOT_FOUND,
+    ELFLOADER_ERR_OUT_OF_MEMORY,
+    ELFLOADER_ERR_PTR_NULL,
+} el_err_t;
+
+#endif /* _TOS_ELFLOADER_ERR_H_ */
+