test(e2e): a tool read from build.ninja is run as a command line

For a compiler without its own library search path the binding starts with
`env LD_LIBRARY_PATH=...` (D29); the resource round-trip (mingw-cross) and
e2e 188 ran the binding as one program name.

Author: Sunrisepeak

tests/e2e/188_build_actions.sh

@@ -298,6 +298,8 @@ EOF
 printf 'int main() { return 0; }\n' > src/main.cpp
 "$MCPP" build > o0.log 2>&1 || { cat o0.log; echo "FAIL: probe build failed"; exit 1; }
 OBJ_NINJA=$(find target -name build.ninja | head -1)
+# A command line, written into mkobj.sh as one: it may start with
+# `env LD_LIBRARY_PATH=...` for a compiler without its own search path.
 OBJ_CXX=$(sed -n 's/^cxx *= *//p' "$OBJ_NINJA" | head -1)
 [ -n "$OBJ_CXX" ] || { cat "$OBJ_NINJA"; echo "FAIL: could not read the compiler out of build.ninja"; exit 1; }
 
@@ -311,7 +313,7 @@ printf 'extern "C" int blob_value() { return 7; }\n' > blob.cpp
 cat > mkobj.sh <<EOF
 #!/usr/bin/env bash
 # \$1 = source, \$2 = object to produce
-"$OBJ_CXX" -c "\$1" -o "\$2"
+$OBJ_CXX -c "\$1" -o "\$2"
 EOF
 chmod +x mkobj.sh
 cat > build.mcpp <<'EOF'

tests/e2e/_windows_resources_body.sh

@@ -119,7 +119,9 @@ esac
 # The rc tool comes out of build.ninja rather than off PATH: mcpp resolved it
 # payload-relative on purpose (a bare `windres` on PATH is an xlings shim), so
 # asking PATH here would inspect the artifact with a different tool than the one
-# that built it.
+# that built it. The binding is a command line: for a compiler without its own
+# library search path it starts with `env LD_LIBRARY_PATH=...`, so it is run by
+# a shell.
 RC_TOOL=$(sed -n 's/^rc *= *//p' "$BUILD_DIR/build.ninja" | head -1)
 [ -n "$RC_TOOL" ] || fail "no 'rc =' binding in build.ninja" "$BUILD_DIR/build.ninja"
 
@@ -138,7 +140,7 @@ version_name_is() {
 
     # Route 1 — windres back to rc SOURCE. Readable, and no PE parser needed.
     if [ -n "$RC_TOOL" ] \
-       && "$RC_TOOL" -J coff -O rc -i "$1" -o "rt.$2.rc" 2>"rt.$2.err" \
+       && sh -c "$RC_TOOL -J coff -O rc -i \"\$1\" -o \"\$2\"" rc "$1" "rt.$2.rc" 2>"rt.$2.err" \
        && grep -qiE 'VERSIONINFO' "rt.$2.rc"; then
         grep -qE "$_want" "rt.$2.rc" \
             || fail "expected the version resource to be named by $3 in $1" "rt.$2.rc"