Change SANITIZE_TARGET refs from 'coverage' to 'fuzzer'.

Cleanup of references to 'coverage' in build files. Part of a larger
cleanup to make fuzzing work again in the Android build tree.

Also fixed a test issue with emulated TLS with the new changes, and
removed libc.so fuzzer support until a linked bug is fixed
(b/132640749).

Bug: 121042685
Test: With all patches in the bug merged: mmma bionic
Change-Id: I592352fe9210ff811a2660a88cbbfe48d70a1e57
Merged-In: I592352fe9210ff811a2660a88cbbfe48d70a1e57
diff --git a/libm/Android.bp b/libm/Android.bp
index 48b9a5f..6d17e86 100644
--- a/libm/Android.bp
+++ b/libm/Android.bp
@@ -503,7 +503,7 @@
     native_coverage: bionic_coverage,
     sanitize: {
         address: false,
-        coverage: false,
+        fuzzer: false,
         integer_overflow: false,
     },
     stl: "none",