Environment variables not honored in some Makefiles

[TannerFirl]

There's a handful of CC = lines in Makefiles that should be CC ?= so it may be properly overridden by a user's CC environment variable. Examples:

src/components/host_micpower/utils/Makefile:1:CC = gcc
src/components/powercap/utils/Makefile:1:CC = gcc
src/components/rapl/utils/Makefile:1:CC = gcc
src/examples/Makefile:3:CC = gcc
src/examples/Makefile:17:   CC = xlc
src/examples/Makefile.AIX:3:CC = xlc
src/examples/Makefile.IRIX64:3:CC = gcc
src/examples/Makefile.OSF1:3:CC = gcc
src/libperfnec/config.mk:77:#CC=icc
src/libperfnec/config.mk:103:CC=craynv-cray-linux-gnu-gcc
src/libpfm-3.y/config.mk:164:#CC=icc
src/libpfm-3.y/config.mk:190:CC=craynv-cray-linux-gnu-gcc
src/libpfm4/config.mk:189:#CC=icc
src/libpfm4/config.mk:206:CC=clang
src/perfctr-2.6.x/examples/global/Makefile:5:CC=gcc
src/perfctr-2.6.x/examples/perfex/Makefile:5:CC=gcc
src/perfctr-2.6.x/examples/self/Makefile:5:CC=gcc
src/perfctr-2.6.x/examples/signal/Makefile:5:CC=gcc
src/perfctr-2.6.x/usr.lib/Makefile:5:CC=gcc
src/perfctr-2.7.x/examples/global/Makefile:5:CC=gcc
src/perfctr-2.7.x/examples/perfex/Makefile:5:CC=$(CROSS_COMPILE)gcc
src/perfctr-2.7.x/examples/self/Makefile:5:CC=$(CROSS_COMPILE)gcc
src/perfctr-2.7.x/examples/signal/Makefile:5:CC=$(CROSS_COMPILE)gcc
src/perfctr-2.7.x/usr.lib/Makefile:5:CC=$(CROSS_COMPILE)gcc

In addition, fortran tests are not honoring the FFLAGS environment variable. Adding FFLAGS = @FFLAGS@ to src/components/Makefile_comp_tests.target.in appears to fix this issue.

Somewhat related, these 2 conditional blocks in src/components/sde/tests/Makefile and src/components/sysdetect/tests/Makefile could be made more robust by adding an else ifeq check for gfortran-12

ifeq ($(notdir $(F77)),gfortran)
    FFLAGS +=-ffree-form -ffree-line-length-none
else ifeq ($(notdir $(F77)),flang)
    FFLAGS +=-ffree-form
else ifeq ($(findstring $(notdir $(F77)), $(intel_compilers)),)
    FFLAGS +=-free
else ifeq ($(findstring $(notdir $(F77)), $(cray_compilers)),)
    FFLAGS +=-ffree
endif

[gcongiu]

This is a known issue that is not easy to resolve as it would require changing a myriad of files in the build system. Note that the sysdetect test Makefile has been amended to fix a bug with intel and cray fortran compiler flags (see #96)