Define a basic llvm-link + clang environment

Move it from dalvik/vm/translator/runtime/ to build/
Add handling of -march=armv5te and -march=armv5e

core/config.mk

@@ -344,6 +344,9 @@ HOST_GLOBAL_CPPFLAGS += $(HOST_RELEASE_CPPFLAGS)
 TARGET_GLOBAL_CFLAGS += $(TARGET_RELEASE_CFLAGS)
 TARGET_GLOBAL_CPPFLAGS += $(TARGET_RELEASE_CPPFLAGS)
 
+# define llvm tools and global flags
+include $(BUILD_SYSTEM)/llvm_config.mk
+
 PREBUILT_IS_PRESENT := $(if $(wildcard prebuilt/Android.mk),true)
 
 # ###############################################################

core/llvm_config.mk

@@ -0,0 +1,33 @@
+CLANG := $(HOST_OUT_EXECUTABLES)/clang$(HOST_EXECUTABLE_SUFFIX)
+LLVM_LINK := $(HOST_OUT_EXECUTABLES)/llvm-link$(HOST_EXECUTABLE_SUFFIX)
+
+define do-clang-flags-subst
+  TARGET_GLOBAL_CLANG_FLAGS := $(subst $(1),$(2),$(TARGET_GLOBAL_CLANG_FLAGS))
+  HOST_GLOBAL_CLANG_FLAGS := $(subst $(1),$(2),$(HOST_GLOBAL_CLANG_FLAGS))
+endef
+
+define clang-flags-subst
+  $(eval $(call do-clang-flags-subst,$(1),$(2)))
+endef
+
+
+# These seem to cause warnings on clang/LLVM.
+CLANG_CONFIG_UNKNOWN_CFLAGS := \
+  -mthumb-interwork \
+  -fgcse-after-reload \
+  -frerun-cse-after-loop \
+  -frename-registers \
+  -funswitch-loops \
+  -Wa,--noexecstack \
+  -mfpu=vfpv3-d16
+
+# Workaround a SIGSEGV in Lol
+CLANG_CONFIG_UNKNOWN_CFLAGS += -g
+
+# remove unknown flags to define CLANG_FLAGS
+TARGET_GLOBAL_CLANG_FLAGS += $(filter-out $(CLANG_CONFIG_UNKNOWN_CFLAGS),$(TARGET_GLOBAL_CFLAGS))
+HOST_GLOBAL_CLANG_FLAGS += $(filter-out $(CLANG_CONFIG_UNKNOWN_CFLAGS),$(HOST_GLOBAL_CFLAGS))
+
+# llvm does not yet support -march=armv5e nor -march=armv5te, fall back to armv5 or armv5t
+$(call clang-flags-subst,-march=armv5te,-march=armv5t)
+$(call clang-flags-subst,-march=armv5e,-march=armv5)