GCC 16 devirtualizes `new FastSourceLineResolver::Module(...)` inside
FastModuleFactory::CreateModule (src/processor/source_line_resolver_base.cc),
which now requires the vtable for FastSourceLineResolver::Module. That vtable
lives in src/processor/fast_source_line_resolver.o, which is not in the LDADD
of the microdump_stackwalk and minidump_stackwalk targets, causing an
undefined reference at link time. Add the object to both LDADD blocks.

Bug: https://bugs.gentoo.org/963936
--- a/Makefile.am
+++ b/Makefile.am
@@ -1448,6 +1448,7 @@
 	src/processor/process_state.o \
 	src/processor/simple_symbol_supplier.o \
 	src/processor/source_line_resolver_base.o \
+	src/processor/fast_source_line_resolver.o \
 	src/processor/stack_frame_cpu.o \
 	src/processor/stack_frame_symbolizer.o \
 	src/processor/stackwalk_common.o \
@@ -1495,6 +1496,7 @@
 	src/processor/proc_maps_linux.o \
 	src/processor/simple_symbol_supplier.o \
 	src/processor/source_line_resolver_base.o \
+	src/processor/fast_source_line_resolver.o \
 	src/processor/stack_frame_cpu.o \
 	src/processor/stack_frame_symbolizer.o \
 	src/processor/stackwalk_common.o \