gdb: Use termux-provided bin/sh instead of system

packages/gdb/build.sh

@@ -2,6 +2,7 @@ TERMUX_PKG_HOMEPAGE=https://www.gnu.org/software/gdb/
 TERMUX_PKG_DESCRIPTION="The standard GNU Debugger that runs on many Unix-like systems and works for many programming languages"
 TERMUX_PKG_DEPENDS="liblzma, libexpat, readline"
 TERMUX_PKG_VERSION=7.9.1
+TERMUX_PKG_BUILD_REVISION=1
 TERMUX_PKG_SRCURL=http://ftp.gnu.org/gnu/gdb/gdb-${TERMUX_PKG_VERSION}.tar.xz
 # gdb can not build with our normal --disable-static: https://sourceware.org/bugzilla/show_bug.cgi?id=15916
 TERMUX_PKG_EXTRA_CONFIGURE_ARGS="--with-system-readline --with-curses --enable-static ac_cv_func_getpwent=no ac_cv_func_getpwnam=no"

packages/gdb/cli_cmds_c_bin_sh.patch

@@ -6,7 +6,7 @@ diff -u -r ../gdb-7.6.2/gdb/cli/cli-cmds.c ./gdb/cli/cli-cmds.c
  
        if ((user_shell = (char *) getenv ("SHELL")) == NULL)
 -	user_shell = "/bin/sh";
-+	user_shell = "/system/bin/sh";
++	user_shell = "@TERMUX_PREFIX@/bin/sh";
  
        /* Get the name of the shell for arg0.  */
        p = lbasename (user_shell);

packages/gdb/fork_child_bin_sh.patch

@@ -6,6 +6,6 @@ diff -u -r ../gdb-7.6.2/gdb/fork-child.c ./gdb/fork-child.c
  
  /* This just gets used as a default if we can't find SHELL.  */
 -#define SHELL_FILE "/bin/sh"
-+#define SHELL_FILE "/system/bin/sh"
++#define SHELL_FILE "@TERMUX_PREFIX@/bin/sh"
  
  extern char **environ;