internal/rosa: remove legacy exec helper

This change also adds a fourth stage to the bootstrap machinery, offering more correct toolchain validation that works around LLVM dynamic linking flaws.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/rosa/package/gnu.az

@@ -17,9 +17,11 @@ package m4 {
 chmod +w tests/test-c32ispunct.sh && echo '#!/bin/sh' > tests/test-c32ispunct.sh
 `;
 
-	exec = make {};
-
 	toyboxEarly = true;
+	exec = make {
+		omitDefaults = true;
+	};
+
 	inputs = [
 		diffutils,
 
@@ -194,7 +196,9 @@ test_disable '#!/bin/sh' tests/cmp
 `;
 
 	toyboxEarly = true;
-	exec = make {};
+	exec = make {
+		omitDefaults = true;
+	};
 }
 
 package patch {
@@ -218,7 +222,9 @@ test_disable '#!/bin/sh' tests/need-filename
 `;
 
 	toyboxEarly = true;
-	exec = make {};
+	exec = make {
+		omitDefaults = true;
+	};
 }
 
 package grep {
@@ -328,6 +334,7 @@ package bash {
 
 	toyboxEarly = true;
 	exec = make {
+		omitDefaults = true;
 		configure = {
 			"without-bash-malloc";
 		};
@@ -364,6 +371,7 @@ test_disable 'int main(){return 0;}' gnulib-tests/test-lchown.c
 `;
 
 	exec = make {
+		omitDefaults = true;
 		configure = {
 			"enable-single-binary": "symlinks";
 		};