[gcc/devel/rust/master] README.md: Added experimental flag & updated gccrs path

[Thomas Schwinge <tschwinge@gcc.gnu.org>]

https://gcc.gnu.org/g:78e96b15a5f12554fb1bd7b41b79b13b2dc4f59b

commit 78e96b15a5f12554fb1bd7b41b79b13b2dc4f59b
Author: MAHAD <mahadtxt@gmail.com>
Date:   Tue Jan 17 20:47:26 2023 +0500

    README.md: Added experimental flag & updated gccrs path
    
    (1) There is a need of the flag "-frust-incomplete-and-experimental-compiler-do-not-use" because the rust1 compiler didn't work without this.
    
    (2) The gccrs was not present in the $HOME/gccrs-install/, so updated the path to $HOME/gccrs-install/bin
    
    Signed-off-by: MAHAD <mahadtxt@gmail.com>

Diff:
---
 README.md | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index d55456ece6e..63118c3a91d 100644
--- a/README.md
+++ b/README.md
@@ -80,7 +80,7 @@ $ make
 Running the compiler itself without make install we can simply invoke the compiler proper:
 
 ```bash
-$ ./gcc/rust1 test.rs -frust-debug -frust-dump-parse -Warray-bounds -dumpbase test.rs -mtune=generic -march=x86-64 -O0 -version -fdump-tree-gimple -o test.s -L/lib/x86_64-linux-gnu -L/lib/../lib64 -L/usr/lib/x86_64-linux-gnu -L/usr/lib/../lib64
+$ ./gcc/rust1 test.rs -frust-debug -frust-dump-parse -Warray-bounds -dumpbase test.rs -mtune=generic -march=x86-64 -O0 -version -fdump-tree-gimple -o test.s -L/lib/x86_64-linux-gnu -L/lib/../lib64 -L/usr/lib/x86_64-linux-gnu -L/usr/lib/../lib64 -frust-incomplete-and-experimental-compiler-do-not-use
 ```
 
 To invoke the compiler driver (gccrs) we need to:
@@ -92,8 +92,8 @@ $ make install
 Then invoke the compiler from the installation directory:
 
 ```bash
-$ $HOME/gccrs-install/gccrs -g -O2 -c test.rs -o test.o
-$ $HOME/gccrs-install/gccrs -o test test.o
+$ $HOME/gccrs-install/bin/gccrs -g -O2 -c test.rs -o test.o -frust-incomplete-and-experimental-compiler-do-not-use
+$ $HOME/gccrs-install/bin/gccrs -o test test.o
 ```
 
 You can also setup your shell to automatically find the installed compiler. For example for `bash`,