bsd.compiler.mk: Add a blocks compiler feature.

Sponsored by:	Klara, Inc.
Reviewed by:	jrtc27
Differential Revision:	https://reviews.freebsd.org/D49963

lib/libc/gen/Makefile.inc

@@ -168,7 +168,7 @@ SRCS+= \
 	valloc.c \
 	wordexp.c
 
-.if ${COMPILER_TYPE} == "clang"
+.if ${COMPILER_FEATURES:Mblocks}
 CFLAGS.fts.c= -fblocks
 .endif
 

lib/libc/tests/gen/Makefile

@@ -7,7 +7,7 @@ ATF_TESTS_C+=		fmtcheck2_test
 ATF_TESTS_C+=		fmtmsg_test
 ATF_TESTS_C+=		fnmatch2_test
 ATF_TESTS_C+=		fpclassify2_test
-.if ${COMPILER_TYPE} == "clang"
+.if ${COMPILER_FEATURES:Mblocks}
 ATF_TESTS_C+=		fts_blocks_test
 .endif
 ATF_TESTS_C+=		ftw_test

lib/libc/tests/stdlib/Makefile

@@ -7,7 +7,7 @@ ATF_TESTS_C+=		heapsort_test
 ATF_TESTS_C+=		libc_exit_test
 ATF_TESTS_C+=		mergesort_test
 ATF_TESTS_C+=		qsort_test
-.if ${COMPILER_TYPE} == "clang"
+.if ${COMPILER_FEATURES:Mblocks}
 ATF_TESTS_C+=		qsort_b_test
 .endif
 ATF_TESTS_C+=		qsort_r_compat_test

share/mk/bsd.compiler.mk

@@ -245,6 +245,7 @@ ${X_}COMPILER_FEATURES+=	c++20
 ${X_}COMPILER_FEATURES+=	init-all
 .endif
 .if ${${X_}COMPILER_TYPE} == "clang"
+${X_}COMPILER_FEATURES+=	blocks
 ${X_}COMPILER_FEATURES+=	retpoline
 # PR257638 lld fails with BE compressed debug.  Fixed in main but external tool
 # chains will initially not have the fix.  For now limit the feature to LE