Multiple fixes for 64 bit sections

This changeset attempts to fix a few problems when giving using
the high 32bits of a 64bit section offset. There are likely more
issues (or perhaps regressions) lurking in the muck here. In general,
this moves a few data type declarations to use uplong.  Also, add
support for 64bit mingw32 building under cygwin.  Because native
types are used for 64 bit offsets, this won't fix challenges with
cross compiling from 32bit -> 64bit.

Tested under cygwin, against binary compiled with
-Wl,-Ttext=0xffffff8000000000

Signed-off-by: Andrew Mulbrook <andrew262@gmail.com>

tccrun.c

@@ -36,10 +36,11 @@ static int rt_get_caller_pc(uplong *paddr, ucontext_t *uc, int level);
 static void rt_error(ucontext_t *uc, const char *fmt, ...);
 static int tcc_relocate_ex(TCCState *s1, void *ptr);
 
-#ifdef _WIN64
+#if defined TCC_TARGET_X86_64 && defined TCC_TARGET_PE
 static void win64_add_function_table(TCCState *s1);
 #endif
 
+
 /* ------------------------------------------------------------- */
 /* Do all relocations (needed before using tcc_get_symbol())
    Returns -1 on error. */
@@ -193,7 +194,7 @@ static int tcc_relocate_ex(TCCState *s1, void *ptr)
                          s1->runtime_plt_and_got_offset);
 #endif
 
-#ifdef _WIN64
+#if defined TCC_TARGET_X86_64 && defined TCC_TARGET_PE
     win64_add_function_table(s1);
 #endif
     return 0;
@@ -621,7 +622,8 @@ static void set_exception_handler(void)
     SetUnhandledExceptionFilter(cpu_exception_handler);
 }
 
-#ifdef _WIN64
+#ifdef TCC_TARGET_PE
+#ifdef TCC_TARGET_X86_64
 static void win64_add_function_table(TCCState *s1)
 {
     RtlAddFunctionTable(
@@ -631,6 +633,7 @@ static void win64_add_function_table(TCCState *s1)
         );
 }
 #endif
+#endif
 
 /* return the PC at frame level 'level'. Return non zero if not found */
 static int rt_get_caller_pc(uplong *paddr, CONTEXT *uc, int level)