Make compiler recognize RAKU_HOME environment variable

- Fix a Raku-style mistype

- Get back m_install for Windows

  It's there really for a reason: Rakudo.pm sets it only if needed.

src/main.nqp

@@ -32,6 +32,7 @@ my $install-dir := $execname eq ''
     !! nqp::substr($execname, 0, nqp::rindex($execname, $sep, nqp::rindex($execname, $sep) - 1));
 
 my $perl6-home := $comp.config<static_perl6_home>
+    // nqp::getenvhash<RAKU_HOME>
     // nqp::getenvhash()<PERL6_HOME>
     // $install-dir ~ '/share/perl6';
 if nqp::substr($perl6-home, nqp::chars($perl6-home) - 1) eq $sep {

tools/lib/NQP/Config/Rakudo.pm

@@ -760,7 +760,7 @@ sub _m_for_toolchain {
 
     $self->not_in_context( toolchain => 'toolchain' );
 
-    my @tools = @{ $cfg->prop('toolchains') || () };
+    my @tools = @{ $cfg->prop('toolchains') || [] };
     my $out = "";
 
     for my $tool (@tools) {

tools/templates/moar/Makefile.in

@@ -213,7 +213,7 @@ $(R_SETTING_MOAR): @bsm(PERL6)@@for_specs( @bsm(SETTING_@ucspec@)@)@ $(R_SETTING
 	@noecho@$(CP) @bpm(INST_PERL6_M)@ @nfpq($(DESTDIR)$(PREFIX)/bin/@bpm(RAKU_M)@)@
 	@noecho@$(CP) @bpm(INST_PERL6_DEBUG_M)@ @nfpq($(DESTDIR)$(PREFIX)/bin/@bpm(RAKU_DEBUG_M)@)@
 @if(platform!=windows @for_langalias(@for_toolchain(@insert(Makefile-install)@)@)@
-)@@if(platform==windows @tab@@noecho@$(CP) @nfpq(@moar::libdir@/@moar::moar@)@ @nfpq($(DESTDIR)$(PREFIX)/bin)@)@
+)@@if(platform==windows @m_install@)@
 
 @backend_prefix@-install-post::
 @expand(@clean_old_p6_libs@)@