core: add new ConditionArchitecture() that checks the architecture returned by uname()'s machine field.

src/core/condition.c

@@ -167,6 +167,9 @@ static bool condition_test(Condition *c) {
         case CONDITION_AC_POWER:
                 return condition_test_ac_power(c);
 
+        case CONDITION_ARCHITECTURE:
+                return condition_test_architecture(c);
+
         case CONDITION_NULL:
                 return !c->negate;
 

src/core/load-fragment-gperf.gperf.m4

@@ -153,6 +153,7 @@ Unit.ConditionDirectoryNotEmpty, config_parse_unit_condition_path,   CONDITION_D
 Unit.ConditionFileNotEmpty,      config_parse_unit_condition_path,   CONDITION_FILE_NOT_EMPTY,      0
 Unit.ConditionFileIsExecutable,  config_parse_unit_condition_path,   CONDITION_FILE_IS_EXECUTABLE,  0
 Unit.ConditionKernelCommandLine, config_parse_unit_condition_string, CONDITION_KERNEL_COMMAND_LINE, 0
+Unit.ConditionArchitecture,      config_parse_unit_condition_string, CONDITION_ARCHITECTURE,        0
 Unit.ConditionVirtualization,    config_parse_unit_condition_string, CONDITION_VIRTUALIZATION,      0
 Unit.ConditionSecurity,          config_parse_unit_condition_string, CONDITION_SECURITY,            0
 Unit.ConditionCapability,        config_parse_unit_condition_string, CONDITION_CAPABILITY,          0