Make tcl9thread300.dll available for easier testing with threads #4759

Job	Run time
gcc	6m 4s
gcc	11m 18s
gcc (CFLAGS=-DTCL_NO_DEPRECATED=1)	8m 23s
gcc (CFLAGS=-DTCL_NO_DEPRECATED=1)	8m 23s
msvc	10m 18s
msvc	10m 18s
gcc (--disable-shared)	10m 50s
gcc (--disable-shared)	10m 50s
msvc (CHECKS=nodep)	9m 39s
msvc (CHECKS=nodep)	9m 39s
gcc (--disable-zipfs)	11m 15s
gcc (--disable-zipfs)	11m 15s
msvc (OPTS=static)	8m 38s
msvc (OPTS=static)	8m 38s
gcc (--enable-memorymodule)	10m 17s
gcc (--enable-memorymodule)	10m 17s
msvc (OPTS=memorymodule)	8m 39s
msvc (OPTS=memorymodule)	8m 39s
gcc (--enable-symbols)	9m 38s
gcc (--enable-symbols)	9m 38s
msvc (OPTS=noembed)	9m 2s
msvc (OPTS=noembed)	9m 2s
msvc (OPTS=symbols)	8m 31s
msvc (OPTS=symbols)	8m 31s
gcc (--enable-symbols=mem)	7m 54s
gcc (--enable-symbols=mem)	7m 54s
msvc (OPTS=symbols STATS=compdbg,memdbg)	7m 4s
msvc (OPTS=symbols STATS=compdbg,memdbg)	7m 4s
gcc (--enable-symbols=all)	9m 20s
gcc (--enable-symbols=all)	9m 20s
	4h 36m 18s

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