Armcompiler (#9840)

* Initial compiler support

* added arm.py

* Changed licence to Arm suggested header

* Changed licence to the same as clang.py
Main author of file is Nick Forrington <Nick.Forrington@arm.com>
Minor changes by Srinath Vadlamani <srinath.vadlamani@arm.com>

* compilers: add arm compiler detection to Spack

- added arm.py with support for detecting `armclang` and `armflang`

Co-authored-by: Srinath Vadlamani <srinath.vadlamani@arm.com>

* Changed to using get get_compiler_version

* linking to general cc for arm compiler

* For arm compiler add CFLAGS to use compiler-rt rtlib.

* Escape for special characters in rexep

* Cleaned up for Flake8 to pass.

* libcompiler-rt should be part of the LDFLAGS not CFLAGS

* fixed m4 when using clang to used LDFLAGS.  Fixed comments for arm.py to display compiler --version output with # NOAQ for flakes pass.

* added arm compilers

* proper linked names

var/spack/repos/builtin/packages/m4/package.py

@@ -34,9 +34,11 @@ def configure_args(self):
         spec = self.spec
         args = ['--enable-c++']
 
-        if (spec.satisfies('%clang') or spec.satisfies('%arm')) and not \
-           spec.satisfies('platform=darwin'):
-            args.append('CFLAGS=-rtlib=compiler-rt')
+        if spec.satisfies('%clang') and not spec.satisfies('platform=darwin'):
+            args.append('LDFLAGS=-rtlib=compiler-rt')
+
+        if spec.satisfies('%arm') and not spec.satisfies('platform=darwin'):
+            args.append('LDFLAGS=-rtlib=compiler-rt')
 
         if spec.satisfies('%intel'):
             args.append('CFLAGS=-no-gcc')