Disable heap shim for SyzyASAN builds.

This fixes the build failure on the Win SyzyASAN LKGR caused by https://codereview.chromium.org/2164653002/.

BUG=550886

Review-Url: https://codereview.chromium.org/2241383005
Cr-Original-Commit-Position: refs/heads/master@{#412294}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 0fb851b955098e98cbd7d7c534a88b907ba9d157

config/allocator.gni

@@ -17,7 +17,7 @@ if (is_android || current_cpu == "mipsel" || is_mac || is_ios || is_asan ||
 # the shim. NaCl in particular does seem to link some binaries statically
 # against the debug CRT with "is_nacl=false".
 if ((is_linux || is_android || (is_win && !is_component_build && !is_debug)) &&
-    !is_asan && !is_lsan && !is_tsan && !is_msan) {
+    !is_syzyasan && !is_asan && !is_lsan && !is_tsan && !is_msan) {
   _default_use_experimental_allocator_shim = true
 } else {
   _default_use_experimental_allocator_shim = false