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

libc/Android.bp

@@ -73,6 +73,8 @@ cc_defaults {
     sanitize: {
         address: false,
         integer_overflow: false,
+        // TODO(b/132640749): Fix broken fuzzer support.
+        fuzzer: false,
     },
     native_coverage: false,
     recovery_available: true,

libm/Android.bp

@@ -503,7 +503,7 @@ cc_library {
     native_coverage: bionic_coverage,
     sanitize: {
         address: false,
-        coverage: false,
+        fuzzer: false,
         integer_overflow: false,
     },
     stl: "none",

tests/Android.bp

@@ -235,6 +235,15 @@ cc_test_library {
     cflags: [
         "-fno-emulated-tls",
     ],
+    // With fuzzer builds, compiler instrumentation generates a reference to the
+    // __sancov_lowest_stack variable, which (for now) is defined by the fuzzer
+    // library as an emutls symbol. The -fno-emulated-tls flag above configures
+    // the compiler to reference an ordinary ELF TLS __sancov_lowest_stack
+    // symbol instead, which isn't defined. Disable the fuzzer for this test
+    // until the platform is switched to ELF TLS.
+    sanitize: {
+        fuzzer: false,
+    },
 }
 
 cc_test_library {
@@ -256,6 +265,15 @@ cc_test_library {
     cflags: [
         "-fno-emulated-tls",
     ],
+    // With fuzzer builds, compiler instrumentation generates a reference to the
+    // __sancov_lowest_stack variable, which (for now) is defined by the fuzzer
+    // library as an emutls symbol. The -fno-emulated-tls flag above configures
+    // the compiler to reference an ordinary ELF TLS __sancov_lowest_stack
+    // symbol instead, which isn't defined. Disable the fuzzer for this test
+    // until the platform is switched to ELF TLS.
+    sanitize: {
+        fuzzer: false,
+    },
 }
 
 // -----------------------------------------------------------------------------

tests/libs/Android.bp

@@ -29,7 +29,7 @@ cc_defaults {
     gtest: false,
     sanitize: {
         address: false,
-        coverage: false,
+        fuzzer: false,
     },
     stl: "libc++_static",
     target: {