Modifies path of getting libc++ library for LLVM coverage generation, caused by upstream clang updates.

See https://b.corp.google.com/issues/236023386#comment11,  culprit CL: https://reviews.llvm.org/D126731 and https://reviews.llvm.org/D107799

Change-Id: I6eaad2d97fbd4e2b82765f8f8cbe671943754938
bug: b/249525798
diff --git a/core/Makefile b/core/Makefile
index a802a4c..0e50f49 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -6342,7 +6342,7 @@
 ifeq (true,$(CLANG_COVERAGE))
   LLVM_PROFDATA := $(LLVM_PREBUILTS_BASE)/linux-x86/$(LLVM_PREBUILTS_VERSION)/bin/llvm-profdata
   LLVM_COV := $(LLVM_PREBUILTS_BASE)/linux-x86/$(LLVM_PREBUILTS_VERSION)/bin/llvm-cov
-  LIBCXX := $(LLVM_PREBUILTS_BASE)/linux-x86/$(LLVM_PREBUILTS_VERSION)/lib64/libc++.so.1
+  LIBCXX := $(LLVM_PREBUILTS_BASE)/linux-x86/$(LLVM_PREBUILTS_VERSION)/lib/x86_64-unknown-linux-gnu/libc++.so.1
   # Use llvm-profdata.zip for backwards compatibility with tradefed code.
   LLVM_COVERAGE_TOOLS_ZIP := $(PRODUCT_OUT)/llvm-profdata.zip