Auto merge of #33093 - alexcrichton:rustbuild-rmake, r=nikomatsakis

test: Move run-make tests into compiletest

Forcing them to be embedded in makefiles precludes being able to run them in
rustbuild, and adding them to compiletest gives us a great way to leverage
future enhancements to our "all encompassing test suite runner" as well as just
moving more things into Rust.

All tests are still Makefile-based in the sense that they rely on `make` being
available to run them, but there's no longer any Makefile-trickery to run them
and rustbuild can now run them out of the box as well.

src/test/run-make/issue-22131/Makefile

@@ -2,6 +2,6 @@
 
 all: foo.rs
 	$(RUSTC) --cfg 'feature="bar"' --crate-type lib foo.rs
-	$(HOST_RPATH_ENV) $(RUSTDOC) --test --cfg 'feature="bar"' \
+	$(HOST_RPATH_ENV) '$(RUSTDOC)' --test --cfg 'feature="bar"' \
 		-L $(TMPDIR) foo.rs |\
 		grep -q 'test foo_0 ... ok'

src/test/run-make/tools.mk

@@ -5,7 +5,7 @@ HOST_RPATH_ENV = \
 TARGET_RPATH_ENV = \
     $(LD_LIB_PATH_ENVVAR)="$(TMPDIR):$(TARGET_RPATH_DIR):$($(LD_LIB_PATH_ENVVAR))"
 
-BARE_RUSTC := $(HOST_RPATH_ENV) $(RUSTC)
+BARE_RUSTC := $(HOST_RPATH_ENV) '$(RUSTC)'
 RUSTC := $(BARE_RUSTC) --out-dir $(TMPDIR) -L $(TMPDIR) $(RUSTFLAGS)
 #CC := $(CC) -L $(TMPDIR)
 HTMLDOCCK := $(PYTHON) $(S)/src/etc/htmldocck.py