Compute LLVM_SHLIB_SYMBOL_VERSION using llvm-config

Perhaps an uncomfortable amount of shell splicing here to extract the
symbol version, but this is sufficient to get the correct symbol version
for `USE_SYSTEM_LLVM=1` use cases.

Author: topolarity

src/Makefile

@@ -366,7 +366,12 @@ $(BUILDDIR)/julia_version.h: $(JULIAHOME)/VERSION
 CXXLD = $(CXX) -shared
 
 $(BUILDDIR)/julia.expmap: $(SRCDIR)/julia.expmap.in
-	sed <'$<' >'$@' -e 's/@JULIA_SHLIB_SYMBOL_VERSION@/JL_LIBJULIA_$(SOMAJOR)/'
+	JULIA_SHLIB_SYMBOL_VERSION="JL_LIBJULIA_$(SOMAJOR)"; \
+	LLVM_SHLIB_SYMBOL_VERSION="$(shell nm -D --with-symbol-versions $(shell $(LLVM_CONFIG_HOST) --libfiles --link-shared | awk '{print $1; exit}') | grep _ZN4llvm3Any6TypeId | head -n 1 | sed -e 's/.*@//')"; \
+	sed <'$<' >'$@' -e "s/@JULIA_SHLIB_SYMBOL_VERSION@/$${JULIA_SHLIB_SYMBOL_VERSION}/" \
+		        -e "s/@LLVM_SHLIB_SYMBOL_VERSION@/$${LLVM_SHLIB_SYMBOL_VERSION}/"
+	JULIA_SHLIB_SYMBOL_VERSION="JL_LIBJULIA_$(SOMAJOR)"; \
+	echo $${JULIA_SHLIB_SYMBOL_VERSION}
 
 $(build_shlibdir)/libjulia-internal.$(JL_MAJOR_MINOR_SHLIB_EXT): $(BUILDDIR)/julia.expmap $(OBJS) $(BUILDDIR)/flisp/libflisp.a $(BUILDDIR)/support/libsupport.a $(LIBUV)
 	@$(call PRINT_LINK, $(CXXLD) $(call IMPLIB_FLAGS,$@) $(JCXXFLAGS) $(JL_CXXFLAGS) $(CXXLDFLAGS) $(SHIPFLAGS) $(OBJS) $(RPATH_LIB) -o $@ \

src/julia.expmap.in

@@ -43,7 +43,7 @@
     *;
 };
 
-JL_LLVM_15.0 {
+@LLVM_SHLIB_SYMBOL_VERSION@ {
   global:
     /* Make visible so that linker will merge duplicate definitions across DSO boundaries */
     _ZN4llvm3Any6TypeId*;