Update to clang-4639204

Use clang-4639204 to build the keymaster unit tests.

Test: 'make' after setting up boringssl per instructions in 'Makefile'
Merged-In: I27bcfc46e9fb396d221b7242b0be79017d050ed5
Change-Id: I27bcfc46e9fb396d221b7242b0be79017d050ed5
diff --git a/Makefile b/Makefile
index a3f06d9..1823793 100644
--- a/Makefile
+++ b/Makefile
@@ -42,8 +42,8 @@
 CXXFLAGS +=-std=c++14 -fprofile-arcs -ftest-coverage
 CFLAGS += -fprofile-arcs -ftest-coverage
 else
-CC=$(BASE)/prebuilts/clang/host/linux-x86/clang-4053586/bin/clang
-CXX=$(BASE)/prebuilts/clang/host/linux-x86/clang-4053586/bin/clang++
+CC=$(BASE)/prebuilts/clang/host/linux-x86/clang-4639204/bin/clang
+CXX=$(BASE)/prebuilts/clang/host/linux-x86/clang-4639204/bin/clang++
 CXXFLAGS +=-std=c++14 -DKEYMASTER_CLANG_TEST_BUILD
 CFLAGS += -DKEYMASTER_CLANG_TEST_BUILD
 endif