Fix R_PACKED() macro usage (#16571)

DEVELOPERS.md

@@ -331,6 +331,26 @@ You may use directory-local variables by putting
 
 into `.dir-locals.el`.
 
+## Packed structures
+
+Due to the various differences between platforms and compilers radare2
+has a special helper macro - `R_PACKED()`. Instead of non-portable
+`#pragma pack` or `__attribute__((packed))` it is advised to use this macro
+instead. To wrap the code inside of it you just need to write:
+```c
+R_PACKED (union mystruct {
+	int a;
+	char b;
+})
+```
+or in case of typedef:
+```c
+R_PACKED (typedef structmystruct {
+	int a;
+	char b;
+})
+```
+
 ## Modules
 
 The radare2 code base is modularized into different libraries that are

libr/bin/format/le/le_specs.h

@@ -47,7 +47,7 @@ typedef struct LE_entry_bundle_header_s {
 #define ENTRY_EXPORTED         0x01
 #define ENTRY_PARAM_COUNT_MASK 0xF8
 
-typedef R_PACKED (union LE_entry_bundle_entry_u {
+R_PACKED (typedef union LE_entry_bundle_entry_u {
 	R_PACKED (struct {
 		ut8 flags;   // First bit set if exported, mask with 0xF8 to get parameters count
 		ut16 offset; // This is the offset in the object for the entry point defined at this ordinal number.

libr/util/protobuf.c

@@ -13,7 +13,7 @@ typedef double ft64;
 #define WIRE_END_GRP   4 // groups (deprecated)
 #define WIRE_32_BIT    5 // fixed32, sfixed32, float
 
-typedef R_PACKED (struct _proto_head {
+R_PACKED (typedef struct _proto_head {
 	ut8 wire   : 3;
 	ut8 number : 5;
 }) proto_head_t;