tree-wide: use 'Architecture' type consistently across the tree

Some parts of our tree used 'Architecture' for storing architectures,
others used ints. Let's unify on the former.

Inspired by #22952's rework of the 'Virtualization' enum.

src/basic/architecture.c

@@ -7,7 +7,7 @@
 #include "string-table.h"
 #include "string-util.h"
 
-int uname_architecture(void) {
+Architecture uname_architecture(void) {
 
         /* Return a sanitized enum identifying the architecture we are running on. This
          * is based on uname(), and the user may hence control what this returns by using
@@ -22,7 +22,7 @@ int uname_architecture(void) {
 
         static const struct {
                 const char *machine;
-                int arch;
+                Architecture arch;
         } arch_map[] = {
 #if defined(__aarch64__) || defined(__arm__)
                 { "aarch64",    ARCHITECTURE_ARM64    },
@@ -122,7 +122,7 @@ int uname_architecture(void) {
 #endif
         };
 
-        static int cached = _ARCHITECTURE_INVALID;
+        static Architecture cached = _ARCHITECTURE_INVALID;
         struct utsname u;
 
         if (cached != _ARCHITECTURE_INVALID)
@@ -175,4 +175,4 @@ static const char *const architecture_table[_ARCHITECTURE_MAX] = {
         [ARCHITECTURE_TILEGX]      = "tilegx",
 };
 
-DEFINE_STRING_TABLE_LOOKUP(architecture, int);
+DEFINE_STRING_TABLE_LOOKUP(architecture, Architecture);

src/basic/architecture.h

@@ -48,7 +48,7 @@ typedef enum {
         _ARCHITECTURE_INVALID = -EINVAL,
 } Architecture;
 
-int uname_architecture(void);
+Architecture uname_architecture(void);
 
 /*
  * LIB_ARCH_TUPLE should resolve to the local library path
@@ -243,5 +243,5 @@ int uname_architecture(void);
 #  error "Please register your architecture here!"
 #endif
 
-const char *architecture_to_string(int a) _const_;
-int architecture_from_string(const char *s) _pure_;
+const char *architecture_to_string(Architecture a) _const_;
+Architecture architecture_from_string(const char *s) _pure_;

src/basic/process-util.c

@@ -1026,7 +1026,7 @@ bool oom_score_adjust_is_valid(int oa) {
 }
 
 unsigned long personality_from_string(const char *p) {
-        int architecture;
+        Architecture architecture;
 
         if (!p)
                 return PERSONALITY_INVALID;
@@ -1050,7 +1050,7 @@ unsigned long personality_from_string(const char *p) {
 }
 
 const char* personality_to_string(unsigned long p) {
-        int architecture = _ARCHITECTURE_INVALID;
+        Architecture architecture = _ARCHITECTURE_INVALID;
 
         if (p == PER_LINUX)
                 architecture = native_architecture();