WT-2938 Change assembly file extensions from .S to .sx (#3072)

build_posix/configure.ac.in

@@ -74,7 +74,7 @@ AM_CONDITIONAL([ARM64_HOST], [test "$wt_cv_arm64" = "yes"])
 # support compiling the ASM code we have to perform the CRC checks on PowerPC.
 # To compile with clang we need to override the ASM compiler with CCAS to use
 # gcc. Unfortunately, doing the compilation in this manner means libtool can't
-# determine what tag to use for that one .S file. If we catch that we are using
+# determine what tag to use for that one .sx file. If we catch that we are using
 # two different compilers for CC and CCAS and we are on a PowerPC system we
 # overload the libtool flags to provide CC by default.
 if test "$wt_cv_powerpc" = "yes" -a "$CC" != "$CCAS"; then

dist/filelist

@@ -48,12 +48,12 @@ src/btree/row_modify.c
 src/btree/row_srch.c
 src/cache/cache_las.c
 src/checksum/arm64/crc32-arm64.c	ARM64_HOST
-src/checksum/power8/crc32.S		POWERPC_HOST
+src/checksum/power8/crc32.sx		POWERPC_HOST
 src/checksum/power8/crc32_wrapper.c	POWERPC_HOST
 src/checksum/software/checksum.c
 src/checksum/x86/crc32-x86.c		X86_HOST
 src/checksum/zseries/crc32-s390x.c	ZSERIES_HOST
-src/checksum/zseries/crc32le-vx.S	ZSERIES_HOST
+src/checksum/zseries/crc32le-vx.sx	ZSERIES_HOST
 src/config/config.c
 src/config/config_api.c
 src/config/config_check.c

src/checksum/power8/README.md

@@ -39,7 +39,7 @@ Quick start
 
 - Type make to create the constants (crc32_constants.h)
 
-- Import the code into your application (crc32.S crc32_wrapper.c
+- Import the code into your application (crc32.sx crc32_wrapper.c
   crc32_constants.h ppc-opcode.h) and call the CRC:
 
 ```