Fixed testsuite Makefile brokenness from 9091a207.

Details:
- Fixed a makefile error encountered when building the testsuite directly
  in its directory (as opposed to indirectly via 'make test'). The fix
  involves introducing a new variable, BUILD_PATH, alongside the existing
  DIST_PATH variable. By default, BUILD_PATH is set to the current
  directory, and is overridden by other Makefiles used by, for example,
  the testsuite and standalone test drivers in testsuite or test,
  respectively.
- Some files/directories in common.mk were redefined in terms of
  BUILD_DIR, such as the locations of config.mk file and the intermediate
  include directory.

common.mk

@@ -128,11 +128,16 @@ files-that-dont-contain = $(strip $(foreach f, $(1), $(if $(findstring $(2),$(f)
 # --- Include makefile configuration file --------------------------------------
 #
 
+# The path to the directory in which BLIS was built.
+ifeq ($(strip $(BUILD_PATH)),)
+BUILD_PATH        := .
+endif
+
 # Define the name of the configuration file.
 CONFIG_MK_FILE     := config.mk
 
 # Include the configuration file.
--include ./$(CONFIG_MK_FILE)
+-include $(BUILD_PATH)/$(CONFIG_MK_FILE)
 
 # Detect whether we actually got the configuration file. If we didn't, then
 # it is likely that the user has not yet generated it (via configure).
@@ -160,7 +165,6 @@ CONFIG_DIR         := config
 FRAME_DIR          := frame
 REFKERN_DIR        := ref_kernels
 KERNELS_DIR        := kernels
-BUILD_DIR          := build
 OBJ_DIR            := obj
 LIB_DIR            := lib
 INCLUDE_DIR        := include
@@ -212,7 +216,7 @@ RANLIB     := ranlib
 INSTALL    := install -c
 
 # Script for creating a monolithic header file.
-FLATTEN_H  := $(DIST_PATH)/$(BUILD_DIR)/flatten-headers.sh
+FLATTEN_H  := $(DIST_PATH)/build/flatten-headers.sh
 
 # Default archiver flags.
 AR         := ar
@@ -485,7 +489,7 @@ MK_HEADER_DIR_PATHS := $(dir $(foreach frag_path, \
 INCLUDE_PATHS   := $(strip $(patsubst %, -I%, $(MK_HEADER_DIR_PATHS)))
 
 # Construct the base path for the intermediate include directory.
-BASE_INC_PATH   := ./$(INCLUDE_DIR)/$(CONFIG_NAME)
+BASE_INC_PATH   := $(BUILD_PATH)/$(INCLUDE_DIR)/$(CONFIG_NAME)
 
 # Isolate the path to blis.h by filtering the file from the list of headers.
 BLIS_H          := blis.h

test/3m4m/Makefile

@@ -55,9 +55,10 @@
 # --- Distribution path override -----------------------------------------------
 #
 
-# Override the DIST_PATH value obtained from config.mk (via common.mk) by
-# defining it here (prior to including the common.mk).
+# Override the default DIST_PATH and BUILD_PATH values so that make can find
+# the source distribution and build location.
 DIST_PATH         := ../..
+BUILD_PATH        := ../..
 
 
 

test/Makefile

@@ -54,9 +54,10 @@
 # --- Distribution path override -----------------------------------------------
 #
 
-# Override the DIST_PATH value obtained from config.mk (via common.mk) by
-# defining it here (prior to including the common.mk).
+# Override the default DIST_PATH and BUILD_PATH values so that make can find
+# the source distribution and build location.
 DIST_PATH         := ..
+BUILD_PATH        := ..
 
 
 

test/exec_sizes/Makefile

@@ -54,9 +54,10 @@
 # --- Distribution path override -----------------------------------------------
 #
 
-# Override the DIST_PATH value obtained from config.mk (via common.mk) by
-# defining it here (prior to including the common.mk).
+# Override the default DIST_PATH and BUILD_PATH values so that make can find
+# the source distribution and build location.
 DIST_PATH         := ../..
+BUILD_PATH        := ../..
 
 
 

test/thread_ranges/Makefile

@@ -54,9 +54,10 @@
 # --- Distribution path override -----------------------------------------------
 #
 
-# Override the DIST_PATH value obtained from config.mk (via common.mk) by
-# defining it here (prior to including the common.mk).
+# Override the default DIST_PATH and BUILD_PATH values so that make can find
+# the source distribution and build location.
 DIST_PATH         := ../..
+BUILD_PATH        := ../..
 
 
 

testsuite/Makefile

@@ -54,9 +54,11 @@
 # --- Distribution path override -----------------------------------------------
 #
 
-# Override the DIST_PATH value obtained from config.mk (via common.mk) by
-# defining it here (prior to including the common.mk).
+# Override the default DIST_PATH and BUILD_PATH values so that make can find
+# the source distribution and build location.
 DIST_PATH         := ..
+BUILD_PATH        := ..
+
 
 
 #
@@ -107,7 +109,7 @@ endif
 #BLIS_INC_PATH  := $(INSTALL_PREFIX)/include/blis
 
 # BLIS library.
-BLIS_LIB_PATH  := $(DIST_PATH)/$(LIB_DIR)/$(CONFIG_NAME)
+BLIS_LIB_PATH  := $(BUILD_PATH)/$(LIB_DIR)/$(CONFIG_NAME)
 BLIS_LIB       := $(BLIS_LIB_PATH)/libblis.a
 
 # BLAS library path(s). This is where the BLAS libraries reside.