configure: Coalesce some arch configuration and PIC handling

configure

@@ -2595,6 +2595,7 @@ pkg_config_default=pkg-config
 ranlib="ranlib"
 strip="strip"
 version_script='--version-script'
+objformat="elf32"
 
 # machine
 arch_default=$(uname -m)
@@ -3766,45 +3767,42 @@ check_64bit(){
     expr=$3
     check_code cc "" "int test[2*($expr) - 1]" &&
         subarch=$arch64 || subarch=$arch32
+    enable $subarch
 }
 
 case "$arch" in
     aarch64|alpha|ia64)
-        spic=$shared
+        enabled shared && enable_weak pic
     ;;
     mips)
         check_64bit mips mips64 '_MIPS_SIM > 1'
-        spic=$shared
+        enabled shared && enable_weak pic
     ;;
     parisc)
         check_64bit parisc parisc64 'sizeof(void *) > 4'
-        spic=$shared
+        enabled shared && enable_weak pic
     ;;
     ppc)
         check_64bit ppc ppc64 'sizeof(void *) > 4'
-        spic=$shared
+        enabled shared && enable_weak pic
     ;;
     s390)
         check_64bit s390 s390x 'sizeof(void *) > 4'
-        spic=$shared
+        enabled shared && enable_weak pic
     ;;
     sparc)
         check_64bit sparc sparc64 'sizeof(void *) > 4'
-        spic=$shared
+        enabled shared && enable_weak pic
     ;;
     x86)
         check_64bit x86_32 x86_64 'sizeof(void *) > 4'
-        if test "$subarch" = "x86_64"; then
-            spic=$shared
+        if enabled x86_64; then
+            enabled shared && enable_weak pic
+            objformat=elf64
         fi
     ;;
 esac
 
-enable $subarch
-enabled spic && enable_weak pic
-
-enabled x86_64 && objformat=elf64 || objformat="elf32"
-
 # OS specific
 case $target_os in
     aix)