Build compiler with -Dexecution_context on Windows (#16502)

Author: straight-shoota

Makefile.win

@@ -61,7 +61,7 @@ SPEC_SOURCES := $(call GLOB,spec\\*.cr)
 override FLAGS += -D strict_multi_assign -D preview_overload_order $(if $(release),--release )$(if $(stats),--stats )$(if $(progress),--progress )$(if $(threads),--threads $(threads) )$(if $(debug),-d )$(if $(static),--static )$(if $(LDFLAGS),--link-flags="$(LDFLAGS)" )$(if $(target),--cross-compile --target $(target) )
 # NOTE: USE_PCRE1 is only used for testing compatibility with legacy environments that don't provide libpcre2.
 # Newly built compilers should never be distributed with libpcre to ensure syntax consistency.
-override COMPILER_FLAGS += $(if $(interpreter),,-Dwithout_interpreter )$(if $(docs_sanitizer),,-Dwithout_libxml2 ) -Dwithout_openssl -Dwithout_zlib$(if $(sequential_codegen),, -Dpreview_mt) $(if $(USE_PCRE1),-Duse_pcre,-Duse_pcre2)
+override COMPILER_FLAGS += $(if $(interpreter),,-Dwithout_interpreter )$(if $(docs_sanitizer),,-Dwithout_libxml2 ) -Dwithout_openssl -Dwithout_zlib$(if $(sequential_codegen),, -Dpreview_mt -Dexecution_context) $(if $(USE_PCRE1),-Duse_pcre,-Duse_pcre2)
 SPEC_WARNINGS_OFF := --exclude-warnings spec\std --exclude-warnings spec\compiler --exclude-warnings spec\primitives --exclude-warnings src\float\printer
 SPEC_FLAGS := $(if $(verbose),-v )$(if $(junit_output),--junit_output $(junit_output) )$(if $(order),--order=$(order) )
 CRYSTAL_CONFIG_LIBRARY_PATH := $$ORIGIN\lib