use signed char rather than plain char for int8_t

otherwise this BADLY breaks if -funsigned-char is passed to gcc

arch/arm/bits/alltypes.h.sh

@@ -29,10 +29,10 @@ TYPEDEF int wint_t;
 TYPEDEF long wctrans_t;
 TYPEDEF long wctype_t;
 
-TYPEDEF char      int8_t;
-TYPEDEF short     int16_t;
-TYPEDEF int       int32_t;
-TYPEDEF long long int64_t;
+TYPEDEF signed char int8_t;
+TYPEDEF short       int16_t;
+TYPEDEF int         int32_t;
+TYPEDEF long long   int64_t;
 
 TYPEDEF unsigned char      uint8_t;
 TYPEDEF unsigned short     uint16_t;

arch/i386/bits/alltypes.h.sh

@@ -37,10 +37,10 @@ TYPEDEF long wint_t;
 TYPEDEF long wctrans_t;
 TYPEDEF long wctype_t;
 
-TYPEDEF char      int8_t;
-TYPEDEF short     int16_t;
-TYPEDEF int       int32_t;
-TYPEDEF long long int64_t;
+TYPEDEF signed char int8_t;
+TYPEDEF short       int16_t;
+TYPEDEF int         int32_t;
+TYPEDEF long long   int64_t;
 
 TYPEDEF unsigned char      uint8_t;
 TYPEDEF unsigned short     uint16_t;

arch/x86_64/bits/alltypes.h.sh

@@ -28,10 +28,10 @@ TYPEDEF int wint_t;
 TYPEDEF int wctrans_t;
 TYPEDEF int wctype_t;
 
-TYPEDEF char      int8_t;
-TYPEDEF short     int16_t;
-TYPEDEF int       int32_t;
-TYPEDEF long      int64_t;
+TYPEDEF signed char int8_t;
+TYPEDEF short       int16_t;
+TYPEDEF int         int32_t;
+TYPEDEF long        int64_t;
 
 TYPEDEF unsigned char      uint8_t;
 TYPEDEF unsigned short     uint16_t;