Make build hermetic without shell scripts

- Fix some minor issues in ar.com
- Have execve() look for `ape` command
- Rewrite NT paths using /c/ rather /??/c:/
- Replace broken GCC symlinks with .sym files
- Rewrite $PATH environment variables on startup
- Make $(APE_NO_MODIFY_SELF) the default bootloader
- Add all build command dependencies to build/bootstrap
- Get the repository mostly building from source on non-Linux

test/tool/args/test.mk

@@ -66,7 +66,7 @@ o/$(MODE)/test/tool/args/%.com.dbg:		\
 		$(TEST_TOOL_ARGS_A).pkg		\
 		$(LIBC_TESTMAIN)		\
 		$(CRT)				\
-		$(APE)
+		$(APE_NO_MODIFY_SELF)
 	@$(APELINK)
 
 .PHONY: o/$(MODE)/test/tool/args

test/tool/build/lib/test.mk

@@ -66,7 +66,7 @@ o/$(MODE)/test/tool/build/lib/%.com.dbg:			\
 		$(TEST_TOOL_BUILD_LIB_A).pkg			\
 		$(LIBC_TESTMAIN)				\
 		$(CRT)						\
-		$(APE)
+		$(APE_NO_MODIFY_SELF)
 	@$(APELINK)
 
 .PHONY: o/$(MODE)/test/tool/build/lib

test/tool/net/test.mk

@@ -68,7 +68,7 @@ o/$(MODE)/test/tool/net/%.com.dbg:			\
 		$(TEST_TOOL_NET_A).pkg			\
 		$(LIBC_TESTMAIN)			\
 		$(CRT)					\
-		$(APE)
+		$(APE_NO_MODIFY_SELF)
 	@$(APELINK)
 
 .PHONY: o/$(MODE)/test/tool/net

test/tool/plinko/test.mk

@@ -74,7 +74,7 @@ o/$(MODE)/test/tool/plinko/%.com.dbg:				\
 		$(TEST_TOOL_PLINKO_A).pkg			\
 		$(LIBC_TESTMAIN)				\
 		$(CRT)						\
-		$(APE)
+		$(APE_NO_MODIFY_SELF)
 	@$(APELINK)
 
 o/$(MODE)/test/tool/plinko/plinko_test.com.runs:		\

test/tool/viz/lib/test.mk

@@ -55,7 +55,7 @@ o/$(MODE)/test/tool/viz/lib/%.com.dbg:			\
 		o/$(MODE)/test/tool/viz/lib/vizlib.pkg	\
 		$(LIBC_TESTMAIN)			\
 		$(CRT)					\
-		$(APE)
+		$(APE_NO_MODIFY_SELF)
 	@$(APELINK)
 
 .PHONY:		o/$(MODE)/test/tool/viz/lib