[MTE] [gnu make] Add memtag_globals as a sanitizer target.

GNU make bits for https://android-review.git.corp.google.com/c/platform/build/soong/+/2625692.

Bug: N/A
Test: Build {libc, libm, libc++, libm, and libnetd} in internal master
with these patches and an experimental compiler with the lld support.
Also, `SANITIZE_TARGET=memtag_globals m` here with in-tree compiler
without lld support.

Change-Id: I44c239ba907a90a355c46e12afbbbe96bb2e4426
diff --git a/core/config_sanitizers.mk b/core/config_sanitizers.mk
index 0e84f516..fb3eb92 100644
--- a/core/config_sanitizers.mk
+++ b/core/config_sanitizers.mk
@@ -176,6 +176,7 @@
 ifneq ($(filter address,$(my_sanitize)),)
   my_sanitize := $(filter-out cfi,$(my_sanitize))
   my_sanitize := $(filter-out memtag_stack,$(my_sanitize))
+  my_sanitize := $(filter-out memtag_globals,$(my_sanitize))
   my_sanitize := $(filter-out memtag_heap,$(my_sanitize))
   my_sanitize_diag := $(filter-out cfi,$(my_sanitize_diag))
 endif
@@ -183,8 +184,8 @@
 # Disable memtag for host targets. Host executables in AndroidMk files are
 # deprecated, but some partners still have them floating around.
 ifdef LOCAL_IS_HOST_MODULE
-  my_sanitize := $(filter-out memtag_heap memtag_stack,$(my_sanitize))
-  my_sanitize_diag := $(filter-out memtag_heap memtag_stack,$(my_sanitize_diag))
+  my_sanitize := $(filter-out memtag_heap memtag_stack memtag_globals,$(my_sanitize))
+  my_sanitize_diag := $(filter-out memtag_heap memtag_stack memtag_globals,$(my_sanitize_diag))
 endif
 
 # Disable sanitizers which need the UBSan runtime for host targets.
@@ -219,11 +220,13 @@
   my_sanitize := $(filter-out hwaddress,$(my_sanitize))
   my_sanitize := $(filter-out memtag_heap,$(my_sanitize))
   my_sanitize := $(filter-out memtag_stack,$(my_sanitize))
+  my_sanitize := $(filter-out memtag_globals,$(my_sanitize))
 endif
 
 ifneq ($(filter hwaddress,$(my_sanitize)),)
   my_sanitize := $(filter-out address,$(my_sanitize))
   my_sanitize := $(filter-out memtag_stack,$(my_sanitize))
+  my_sanitize := $(filter-out memtag_globals,$(my_sanitize))
   my_sanitize := $(filter-out memtag_heap,$(my_sanitize))
   my_sanitize := $(filter-out thread,$(my_sanitize))
   my_sanitize := $(filter-out cfi,$(my_sanitize))
@@ -240,7 +243,7 @@
   endif
 endif
 
-ifneq ($(filter memtag_heap memtag_stack,$(my_sanitize)),)
+ifneq ($(filter memtag_heap memtag_stack memtag_globals,$(my_sanitize)),)
   ifneq ($(filter memtag_heap,$(my_sanitize_diag)),)
     my_cflags += -fsanitize-memtag-mode=sync
     my_sanitize_diag := $(filter-out memtag_heap,$(my_sanitize_diag))
@@ -262,6 +265,14 @@
   my_sanitize := $(filter-out memtag_stack,$(my_sanitize))
 endif
 
+ifneq ($(filter memtag_globals,$(my_sanitize)),)
+  my_cflags += -fsanitize=memtag-globals
+  # TODO(mitchp): For now, enable memtag-heap with memtag-globals because the
+  # linker isn't new enough
+  # (https://reviews.llvm.org/differential/changeset/?ref=4243566).
+  my_sanitize := $(filter-out memtag_globals,$(my_sanitize))
+endif
+
 # TSAN is not supported on 32-bit architectures. For non-multilib cases, make
 # its use an error. For multilib cases, don't use it for the 32-bit case.
 ifneq ($(filter thread,$(my_sanitize)),)