tcc: re-enable correct option -r support

Forgot about it.  It allows to compile several
sources (and other .o's) to one single .o file;

    tcc -r -o all.o f1.c f2.c f3.S o4.o ...

Also:
- option -fold-struct-init-code removed, no effect anymore
- (tcc_)set_environment() moved to tcc.c
- win32/lib/(win)crt1 minor fix & add dependency
- debug line output for asm (tcc -c -g xxx.S) enabled
- configure/Makefiles: x86-64 -> x86_64 changes
- README: cleanup

README

@@ -28,28 +28,19 @@ Features:
 Documentation:
 -------------
 
-1) Installation on a i386/x86_64/arm Linux/OSX/FreeBSD host (for Windows read tcc-win32.txt)
-
-Note: For OSX and FreeBSD, gmake should be used instead of make.
+1) Installation on a i386/x86_64/arm Linux/OSX/FreeBSD host
 
    ./configure
    make
    make test
    make install
 
-Alternatively, out-of-tree builds are supported: you may use different
-directories to hold build objects, kept separate from your source tree:
+   Notes: For OSX and FreeBSD, gmake should be used instead of make.
+   For Windows read tcc-win32.txt.
 
-   mkdir _build
-   cd _build
-   ../configure
-   make
-   make test
-   make install
-
-Texi2html must be installed to compile the doc. 
-By default, tcc is installed in /usr/local/bin.
-./configure --help  shows configuration options.
+makeinfo must be installed to compile the doc.  By default, tcc is
+installed in /usr/local/bin.  ./configure --help  shows configuration
+options.
 
 
 2) Introduction