Fix libinstpatch and sndfile not being discovered on Windows #1045

Job	Run time
build (-Denable-profiling=1)	2m 32s
build (-Denable-floats=1 -Denable-profiling=1)	1m 34s
build (-Denable-floats=1)	50s
build (-Denable-trap-on-fpe=1)	1m 10s
build (-Denable-fpe-check=1)	56s
build (-Denable-ipv6=0)	49s
build (-Denable-network=0)	52s
build (-Denable-aufile=0)	2m 28s
build (-DBUILD_SHARED_LIBS=0)	52s
build (-Denable-ubsan=1 -Denable-debug=1)	2m 0s
build (-Denable-debug=1 -DCMAKE_C_FLAGS_DEBUG=-fuse-ld=gold)	1m 19s
build (clang-7, clang++-7)	1m 14s
build (clang-8, clang++-8)	59s
build (clang-10, clang++-10)	50s
build (clang-12, clang++-12)	1m 5s
build (clang-10, clang++-10, -DBUILD_SHARED_LIBS=0)	1m 7s
	20m 37s

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