Add option to select 64-bit build platform

arch/sim/Kconfig

@@ -7,7 +7,8 @@ if ARCH_SIM
 comment "Simulation Configuration Options"
 
 config SIM_M32
-	bool "Build 32-bit simulation on 64-bit machine"
+#	bool "Build 32-bit simulation on 64-bit machine"
+	bool
 	default n
 	---help---
 		Simulation context switching is based on logic like setjmp and longjmp.  This
@@ -19,6 +20,19 @@ config SIM_M32
 		beyond.  For thoses versions, you must add SIM_M32=y to the .config file in
 		order to enable building a 32-bit image on a 64-bit platform.
 
+choice
+	prompt "Host CPU Type"
+	default HOST_X86_64
+
+config HOST_X86_64
+	bool "x86_64"
+	select SIM_M32
+
+config HOST_X86
+	bool "x86"
+
+endchoice # Host CPU Type
+
 config SIM_WALLTIME
 	bool "Execution simulation in near real-time"
 	default n

arch/sim/include/types.h

@@ -76,7 +76,7 @@ typedef signed long long   _int64_t;
 typedef unsigned long long _uint64_t;
 #define __INT64_DEFINED
 
-#ifdef CONFIG_SIM_M32
+#ifdef CONFIG_HOST_X86_64
 /* 32-bit build on 64-bit machine: A pointer is 8 bytes */
 
 typedef signed long long   _intptr_t;