LLVM 12 big math test workaround.

tests/core/math/big/build.bat

@@ -2,6 +2,7 @@
 rem math/big tests
 set PATH_TO_ODIN==..\..\..\..\odin
 set TEST_ARGS=-fast-tests
+set TEST_ARGS=-no-random
 set TEST_ARGS=
 set OUT_NAME=math_big_test_library
 set COMMON=-build-mode:shared -show-timings -no-bounds-check -define:MATH_BIG_EXE=false -vet -strict-style
@@ -9,5 +10,8 @@ echo ---
 echo Running core:math/big tests
 echo ---
 
-%PATH_TO_ODIN% build . %COMMON% -o:speed -out:%OUT_NAME%
+rem Fails
+:%PATH_TO_ODIN% build . %COMMON% -o:speed -out:%OUT_NAME%
+rem Passes
+%PATH_TO_ODIN% build . %COMMON% -o:size -out:%OUT_NAME%
 python3 test.py %TEST_ARGS%