Force external asn1_compile and compile_et binaries.
At the moment the samba bundled heimdal fails to build the tools for the host
when cross-compiling, and it can't link to an external heimdal either.

Status: working with samba upstream on a proper way to cross-compile
the bundled heimdal.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>

Index: samba-4.11.2/third_party/heimdal_build/wscript_build
===================================================================
--- samba-4.11.2.orig/third_party/heimdal_build/wscript_build
+++ samba-4.11.2/third_party/heimdal_build/wscript_build
@@ -941,6 +941,8 @@ if not bld.CONFIG_SET('USING_SYSTEM_ASN1
         install=False
     )
     bld.env['ASN1_COMPILE'] = os.path.join(bld.bldnode.parent.abspath(), 'asn1_compile')
+else:
+    bld.env['ASN1_COMPILE'] = 'asn1_compile'
 
 
 if not bld.CONFIG_SET('USING_SYSTEM_COMPILE_ET'):
@@ -955,6 +957,8 @@ if not bld.CONFIG_SET('USING_SYSTEM_COMP
         install=False
         )
     bld.env['COMPILE_ET'] = os.path.join(bld.bldnode.parent.abspath(), 'compile_et')
+else:
+    bld.env['COMPILE_ET'] = 'compile_et'
 
 HEIMDAL_BINARY('samba4kinit',
     'kuser/kinit.c',
Index: work/factory/factory-20190823-rpi/build_armv7l-timesys-linux-gnueabihf/samba4-4.11.2/samba-4.11.2/third_party/heimdal_build/wscript_configure
===================================================================
--- samba-4.11.2.orig/third_party/heimdal_build/wscript_configure
+++ samba-4.11.2/third_party/heimdal_build/wscript_configure
@@ -156,6 +156,8 @@ conf.define('HAVE_ENCTYPE_AES256_CTS_HMA
 conf.define('HAVE_KRB5_PRINCIPAL_GET_NUM_COMP', 1)
 conf.define('HAVE_GSSAPI_GSSAPI_SPNEGO_H', 1)
 conf.define('HAVE_FLAGS_IN_KRB5_CREDS', 1)
+conf.define('USING_SYSTEM_ASN1_COMPILE', 1)
+conf.define('USING_SYSTEM_COMPILE_ET', 1)
 conf.define('HAVE_KRB5_CONFIG_GET_BOOL_DEFAULT', 1)
 conf.define('HAVE_KRB5_DATA_COPY', 1)
 conf.define('HAVE_KRB5_PRINCIPAL_SET_REALM', 1)