Revert "configure: allow building with python3"

This reverts commit ae7898dfdbe5c8dab7d11c71862353f1ae43feb0.

Turns out the python scripts are _not_ fully python 3 compatible.
As Ilia reported using get_xmlpool.py with LANG=C produces some weird
output - see the link for details.

Even though the issue was spotted with the autoconf build, it exposes a
genuine problem with the script (and lack of lang handling of the meson
build.)

https://lists.freedesktop.org/archives/mesa-dev/2018-August/203508.html

5 files changed, 5 insertions, 5 deletions

diff --git a/src/gallium/auxiliary/Makefile.am b/src/gallium/auxiliary/Makefile.am
index d7d803a961c..4bfa7648389 100644
--- a/src/gallium/auxiliary/Makefile.am
+++ b/src/gallium/auxiliary/Makefile.am
@@ -54,7 +54,7 @@ libgallium_la_SOURCES += \
 endif
 
 MKDIR_GEN = $(AM_V_at)$(MKDIR_P) $(@D)
-PYTHON_GEN =  $(AM_V_GEN)$(PYTHON) $(PYTHON_FLAGS)
+PYTHON_GEN =  $(AM_V_GEN)$(PYTHON2) $(PYTHON_FLAGS)
 
 indices/u_indices_gen.c: indices/u_indices_gen.py
 	$(MKDIR_GEN)
diff --git a/src/gallium/drivers/freedreno/Makefile.am b/src/gallium/drivers/freedreno/Makefile.am
index 67095de6e0f..c19b776892c 100644
--- a/src/gallium/drivers/freedreno/Makefile.am
+++ b/src/gallium/drivers/freedreno/Makefile.am
@@ -12,7 +12,7 @@ AM_CFLAGS = \
 MKDIR_GEN = $(AM_V_at)$(MKDIR_P) $(@D)
 ir3/ir3_nir_trig.c: ir3/ir3_nir_trig.py $(top_srcdir)/src/compiler/nir/nir_algebraic.py
 	$(MKDIR_GEN)
-	$(AM_V_GEN) $(PYTHON) $(PYTHON_FLAGS) $(srcdir)/ir3/ir3_nir_trig.py -p $(top_srcdir)/src/compiler/nir > $@ || ($(RM) $@; false)
+	$(AM_V_GEN) $(PYTHON2) $(PYTHON_FLAGS) $(srcdir)/ir3/ir3_nir_trig.py -p $(top_srcdir)/src/compiler/nir > $@ || ($(RM) $@; false)
 
 noinst_LTLIBRARIES = libfreedreno.la
 
diff --git a/src/gallium/drivers/r600/Makefile.am b/src/gallium/drivers/r600/Makefile.am
index c5b41cce26e..1138de985dd 100644
--- a/src/gallium/drivers/r600/Makefile.am
+++ b/src/gallium/drivers/r600/Makefile.am
@@ -3,7 +3,7 @@ include $(top_srcdir)/src/gallium/Automake.inc
 
 egd_tables.h: $(srcdir)/egd_tables.py $(srcdir)/evergreend.h
 	$(AM_V_at)$(MKDIR_P) $(@D)
-	$(AM_V_GEN) $(PYTHON) $(srcdir)/egd_tables.py $(srcdir)/evergreend.h > $@
+	$(AM_V_GEN) $(PYTHON2) $(srcdir)/egd_tables.py $(srcdir)/evergreend.h > $@
 
 BUILT_SOURCES = $(R600_GENERATED_FILES)
 AM_CFLAGS = \
diff --git a/src/gallium/drivers/radeonsi/Makefile.am b/src/gallium/drivers/radeonsi/Makefile.am
index 317ae7ea19f..62b877d4ea4 100644
--- a/src/gallium/drivers/radeonsi/Makefile.am
+++ b/src/gallium/drivers/radeonsi/Makefile.am
@@ -48,7 +48,7 @@ GEN_DRIINFO_INPUTS = \
 	$(top_srcdir)/src/gallium/auxiliary/pipe-loader/driinfo_gallium.h \
 	$(srcdir)/driinfo_radeonsi.h
 
-PYTHON_GEN = $(AM_V_GEN)$(PYTHON) $(PYTHON_FLAGS)
+PYTHON_GEN = $(AM_V_GEN)$(PYTHON2) $(PYTHON_FLAGS)
 MERGE_DRIINFO = $(top_srcdir)/src/util/merge_driinfo.py
 
 si_driinfo.h: $(MERGE_DRIINFO) $(GEN_DRIINFO_INPUTS)
diff --git a/src/gallium/drivers/swr/Makefile.am b/src/gallium/drivers/swr/Makefile.am
index 3390ef6b096..d20a6bdbed3 100644
--- a/src/gallium/drivers/swr/Makefile.am
+++ b/src/gallium/drivers/swr/Makefile.am
@@ -98,7 +98,7 @@ BUILT_SOURCES = \
 	rasterizer/core/backends/gen_rasterizer.hpp
 
 MKDIR_GEN = $(AM_V_at)$(MKDIR_P) $(@D)
-PYTHON_GEN = $(AM_V_GEN)$(PYTHON) $(PYTHON_FLAGS)
+PYTHON_GEN = $(AM_V_GEN)$(PYTHON2) $(PYTHON_FLAGS)
 gen_swr_context_llvm.h: rasterizer/codegen/gen_llvm_types.py rasterizer/codegen/templates/gen_llvm.hpp swr_context.h
 	$(PYTHON_GEN) \
 		$(srcdir)/rasterizer/codegen/gen_llvm_types.py \