Merge branch 'framework/gfortran_options_cleanup' into hotfix-v7.1 (PR #802)

This merge introduces several minor updates and clean-up changes to the 'gfortran'
build target:

1. Remove the -m64 flag, which is architecture-specific
2. Change -O3 to -g in the definition of CXXFLAGS_DEBUG
3. Enable all available run-time checks with -fcheck=all for debug builds

* framework/gfortran_options_cleanup:
  Enable all runtime checks when DEBUG=true in gfortran build target
  Remove -m64 from all compiler flag sets in gfortran build target
  Change -O3 to -g in CXXFLAGS_DEBUG for gfortran build target

Author: mgduda

Makefile

@@ -219,14 +219,14 @@ gfortran:
 	"CC_SERIAL = gcc" \
 	"CXX_SERIAL = g++" \
 	"FFLAGS_PROMOTION = -fdefault-real-8 -fdefault-double-8" \
-	"FFLAGS_OPT = -O3 -m64 -ffree-line-length-none -fconvert=big-endian -ffree-form" \
-	"CFLAGS_OPT = -O3 -m64" \
-	"CXXFLAGS_OPT = -O3 -m64" \
-	"LDFLAGS_OPT = -O3 -m64" \
-	"FFLAGS_DEBUG = -g -m64 -ffree-line-length-none -fconvert=big-endian -ffree-form -fbounds-check -fbacktrace -ffpe-trap=invalid,zero,overflow" \
-	"CFLAGS_DEBUG = -g -m64" \
-	"CXXFLAGS_DEBUG = -O3 -m64" \
-	"LDFLAGS_DEBUG = -g -m64" \
+	"FFLAGS_OPT = -O3 -ffree-line-length-none -fconvert=big-endian -ffree-form" \
+	"CFLAGS_OPT = -O3" \
+	"CXXFLAGS_OPT = -O3" \
+	"LDFLAGS_OPT = -O3" \
+	"FFLAGS_DEBUG = -g -ffree-line-length-none -fconvert=big-endian -ffree-form -fcheck=all -fbacktrace -ffpe-trap=invalid,zero,overflow" \
+	"CFLAGS_DEBUG = -g" \
+	"CXXFLAGS_DEBUG = -g" \
+	"LDFLAGS_DEBUG = -g" \
 	"FFLAGS_OMP = -fopenmp" \
 	"CFLAGS_OMP = -fopenmp" \
 	"CORE = $(CORE)" \