dev-lang/quickjs: Remove hard-coded tools, make it respect flags.

Closes: https://bugs.gentoo.org/784941
Closes: https://bugs.gentoo.org/781008
Signed-off-by: Ronny (tastytea) Gutbrod <gentoo@tastytea.de>

dev-lang/quickjs/quickjs-2020.11.08.ebuild

@@ -3,6 +3,8 @@
 
 EAPI=7
 
+inherit toolchain-funcs
+
 MY_P="${PN}-${PV//./-}"
 
 DESCRIPTION="Small embeddable Javascript engine"
@@ -19,5 +21,14 @@ src_prepare() {
 		-e '/$(STRIP) .*/d' \
 		Makefile || die "Failed setting prefix"
 
+	sed -Ei '/^\s*(CC|AR)=/d' Makefile \
+		|| die "Failed to remove hard-coded tools."
+
+	sed -Ei 's/(^\s*(C|LD)FLAGS)=/\1\+=/' Makefile \
+		|| die "Failed to change build flag assignment into addition."
+
+	export CC="$(tc-getCC)"
+	export AR="$(tc-getAR)"
+
 	default
 }