Add copy_python_gdb for 3.7.3 and move patches.

Fixes issue introduced in #1283 and #1308.

plugins/python-build/share/python-build/3.7.3

@@ -2,7 +2,7 @@
 install_package "openssl-1.0.2k" "https://www.openssl.org/source/openssl-1.0.2k.tar.gz#6b3977c61f2aedf0f96367dcfb5c6e578cf37e7b8d913b4ecb6643c3cb88d8c0" mac_openssl --if has_broken_mac_openssl
 install_package "readline-6.3" "https://ftpmirror.gnu.org/readline/readline-6.3.tar.gz#56ba6071b9462f980c5a72ab0023893b65ba6debb4eeb475d7a563dc65cafd43" standard --if has_broken_mac_readline
 if has_tar_xz_support; then
-  install_package "Python-3.7.3" "https://www.python.org/ftp/python/3.7.3/Python-3.7.3.tar.xz#da60b54064d4cfcd9c26576f6df2690e62085123826cff2e667e72a91952d318" ldflags_dirs standard verify_py37 ensurepip
+  install_package "Python-3.7.3" "https://www.python.org/ftp/python/3.7.3/Python-3.7.3.tar.xz#da60b54064d4cfcd9c26576f6df2690e62085123826cff2e667e72a91952d318" ldflags_dirs standard verify_py37 copy_python_gdb ensurepip
 else
-  install_package "Python-3.7.3" "https://www.python.org/ftp/python/3.7.3/Python-3.7.3.tgz#d62e3015f2f89c970ac52343976b406694931742fbde2fed8d1ce8ebb4e1f8ff" ldflags_dirs standard verify_py37 ensurepip
-fi
+  install_package "Python-3.7.3" "https://www.python.org/ftp/python/3.7.3/Python-3.7.3.tgz#d62e3015f2f89c970ac52343976b406694931742fbde2fed8d1ce8ebb4e1f8ff" ldflags_dirs standard verify_py37 copy_python_gdb ensurepip
+fi