Audit set of bundled MinGW import libraries

[retep998]

The set of import libraries that Rust bundles should strictly be what is needed to link against the libraries that come with the Rust distribution. Missing an import library causes link errors while including unnecessary import libraries bloats the distribution.

Library	Necessary
libadvapi32.a	Yes
libbcrypt.a	No
libcomctl32.a	No
libcomdlg32.a	No
libcredui.a	Yes and missing!
libcrypt32.a	No
libdbghelp.a	Yes
libgdi32.a	Yes
libimagehlp.a	No
libiphlpapi.a	No
libkernel32.a	Yes
libmsimg32.a	Yes
libmsvcrt.a	Yes
libodbc32.a	No
libole32.a	No
liboleaut32.a	No
libopengl32.a	Yes
libpsapi.a	Yes
librpcrt4.a	No
libsecur32.a	Yes and missing!
libsetupapi.a	Yes
libshell32.a	Yes
libuser32.a	Yes
libuserenv.a	Yes
libuuid.a	No
libwinhttp.a	No
libwinmm.a	No
libwinspool.a	Yes
libws2_32.a	Yes
libwsock32.a	No