Compile tests with --sysroot

Gives them access to the `wasi/version.h` header for example

Author: alexcrichton

test/CMakeLists.txt

@@ -34,6 +34,10 @@ else()
   add_custom_target(engine)
 endif()
 
+# All tests are compiled against the wasi-libc sysroot
+add_compile_options(--sysroot ${SYSROOT})
+add_link_options(--sysroot ${SYSROOT})
+
 # ========= libc-test defined tests =============================
 
 function(add_wasilibc_flags target)
@@ -295,6 +299,7 @@ add_wasilibc_test(seekdir.c FS FAILP3)
 add_wasilibc_test(usleep.c)
 add_wasilibc_test(nanosleep.c)
 add_wasilibc_test(write.c FS FAILP3)
+add_wasilibc_test(wasi-defines.c)
 
 if (TARGET_TRIPLE MATCHES "-threads")
   add_wasilibc_test(busywait.c)

test/src/wasi-defines.c

@@ -0,0 +1,10 @@
+#include <wasi/version.h>
+
+int main() {
+#if defined(__wasip1__) || defined(__wasip2__) || defined(__wasip3__)
+  return 0;
+#else
+#error "Expected a wasi #define"
+  return 1;
+#endif
+}