Added additional xMessageBufferSpacesAvailable() (plural) to existing xMessageBufferSpaceAvailable() (singular) macro as the documentation muddled both.

Added #define portPOINTER_SIZE_TYPE 	uint64_t to the 64-bit RISC-V port layer.

FreeRTOS/Source/include/message_buffer.h

@@ -692,6 +692,7 @@ size_t xMessageBufferSpaceAvailable( MessageBufferHandle_t xMessageBuffer ) );
  * \ingroup MessageBufferManagement
  */
 #define xMessageBufferSpaceAvailable( xMessageBuffer ) xStreamBufferSpacesAvailable( ( StreamBufferHandle_t ) xMessageBuffer )
+#define xMessageBufferSpacesAvailable( xMessageBuffer ) xStreamBufferSpacesAvailable( ( StreamBufferHandle_t ) xMessageBuffer ) /* Corrects typo in original macro name. */
 
 /**
  * message_buffer.h

FreeRTOS/Source/portable/GCC/RISC-V/portmacro.h

@@ -45,10 +45,11 @@ extern "C" {
 
 /* Type definitions. */
 #if __riscv_xlen == 64
-	#define portSTACK_TYPE	uint64_t
+	#define portSTACK_TYPE			uint64_t
-	#define portBASE_TYPE	int64_t
+	#define portBASE_TYPE			int64_t
-	#define portUBASE_TYPE	uint64_t
+	#define portUBASE_TYPE			uint64_t
-	#define portMAX_DELAY ( TickType_t ) 0xffffffffffffffffUL
+	#define portMAX_DELAY 			( TickType_t ) 0xffffffffffffffffUL
+	#define portPOINTER_SIZE_TYPE 	uint64_t
 #elif __riscv_xlen == 32
 	#define portSTACK_TYPE	uint32_t
 	#define portBASE_TYPE	int32_t