adjust for erroneous detection of nvc as gcc (#24915)

* adjust for erroneous detection of nvc as gcc

adjust for erroneous detection of nvc as gcc when it is built with gcc

* add missing parenthesis :/

* fix trailing whitespace

* re-work hdf5 patch for nvc to make it more general

* flake8 fixes

* Render as comment

Render intended note as a comment rather than logical constraint

Co-authored-by: Frank Willmore <willmore@anl.gov>

var/spack/repos/builtin/packages/hdf5/package.py

@@ -188,11 +188,12 @@ def flag_handler(self, name, flags):
         cmake_flags = []
 
         if name == "cflags":
-            cc_name = os.path.basename(self.compiler.cc)
-            if "clang" in cc_name or "gcc" in cc_name:
+            if self.spec.satisfies('%gcc') \
+                    or self.spec.satisfies('%clang'):
                 # Quiet warnings/errors about implicit declaration of functions
                 # in C99:
                 cmake_flags.append("-Wno-implicit-function-declaration")
+                # Note that this flag will cause an error if building %nvhpc.
             if self.spec.satisfies('@:1.8.12~shared'):
                 # More recent versions set CMAKE_POSITION_INDEPENDENT_CODE to
                 # True and build with PIC flags.